Physical Chemistry for IIT JEE

Atul Singha

Chapter 4

Energetics - all with Video Answers

Educators

Chapter Questions

Problem 1

Under the same conditions how many $\mathrm{ml}$ of $1 \mathrm{M}$ $\mathrm{KOH}$ and $0.5 \mathrm{MH}_{2} \mathrm{SO}_{4}$ solutions, respectively, when mixed to form total volume of $100 \mathrm{ml}$, produces the highest rise in temperature?
a. 67,33
b. 33,67
c. 40,60
d. 50,50

Amita Prajapat

Amita Prajapat

Numerade Educator

Problem 2

Identify the state function among the following:
a. $\mathrm{q}$
b. $\mathrm{q}-\mathrm{w}$
c. $\mathrm{q} / \mathrm{w}$
d. $q+w$

Mahipal Kumawat

Mahipal Kumawat

Numerade Educator

Problem 3

For an endothermic reaction where $\Delta \mathrm{H}$ represents the enthalpy of the reaction in $\mathrm{kJ} / \mathrm{mol}$, the minimum value for the energy of activation will be
a. less than $\Delta \mathrm{H}$
b. zero
c. more than $\Delta \mathrm{H}$
d. equal to $\Delta \mathrm{H}$.

Supratim Pal

Numerade Educator

Problem 4

Which of the following equations represent standard heat of formation of $\mathrm{C}_{2} \mathrm{H}_{4} ?$
a. $2 \mathrm{C}$ (diamond) $+2 \mathrm{H}_{2}(\mathrm{~g}) \rightarrow \mathrm{C}_{2} \mathrm{H}_{4}(\mathrm{~g})$
b. $2 \mathrm{C}$ (graphite) $+2 \mathrm{H}_{2}(\mathrm{~g}) \rightarrow \mathrm{C}_{2} \mathrm{H}_{4}(\mathrm{~g})$
c. $2 \mathrm{C}$ (diamond) $+4 \mathrm{H}(\mathrm{g}) \rightarrow \mathrm{C}_{2} \mathrm{H}_{4}(\mathrm{~g})$
d. $2 \mathrm{C}$ (graphite) $+4 \mathrm{H}(\mathrm{g}) \rightarrow \mathrm{C}_{2} \mathrm{H}_{4}(\mathrm{~g})$

Amita Prajapat

Numerade Educator

Problem 5

A glucose solution in $100 \mathrm{gm}$ of water boils at $100.26^{\circ} \mathrm{C}$. If this solution is heated to $101^{\circ} \mathrm{C}$. What will be the mass of water left at equilibrium?
a. $76 \mathrm{gm}$
b. $120 \mathrm{gm}$
c. $100 \mathrm{gm}$
d. $26 \mathrm{gm}$

Hunza Gilgit

Numerade Educator

Problem 6

The enthalpy of hydrogenation of cyclohexene is $-119.5 \mathrm{~kJ} \mathrm{~mol}^{-1} .$ If resonance energy of benzene is $-150.4 \mathrm{~kJ} \mathrm{~mol}^{-1}$, its enthalpy of hydrogenation would be
a. $-269.9 \mathrm{~kJ} \mathrm{~mol}^{-1}$
b. $-358.5 \mathrm{~kJ} \mathrm{~mol}^{-1}$
c. $-508.9 \mathrm{~kJ} \mathrm{~mol}^{-1}$
d. $-208.1 \mathrm{~kJ} \mathrm{~mol}^{-1}$

Amita Prajapat

Numerade Educator

Problem 7

A reaction is non-spontaneous at the freezing point of water but is spontaneous at the boiling point of water then
a. $+$ ve
b. $-v e$
c. $-v e$
d. tre

Amita Prajapat

Numerade Educator

Problem 8

The enthalpy change $(\Delta \mathrm{H})$ for the reaction,
$\mathrm{N}_{2}(\mathrm{~g})+3 \mathrm{H}_{2}(\mathrm{~g}) \rightarrow 2 \mathrm{NH}_{3}(\mathrm{~g})$
is $-92.38 \mathrm{~kJ}$ at $298 \mathrm{~K}$. The internal energy change $\Delta \mathrm{U}$ at $298 \mathrm{~K}$ is
a. $-92.38 \mathrm{~kJ}$
b. $-87.42 \mathrm{~kJ}$
c. $-97.34 \mathrm{~kJ}$
d. $-89.9 \mathrm{~kJ}$

Amita Prajapat

Numerade Educator

Problem 9

For a phase change
$\mathrm{H}_{2} \mathrm{O}(\mathrm{l}) \leftarrow{0^{\circ} \mathrm{C}, 1 \mathrm{bar}}{\longrightarrow} \mathrm{H}_{2} \mathrm{O}(\mathrm{s})$
a. $\Delta \mathrm{G}=0$
b. $\Delta \mathrm{S}=0$
c. $\Delta \mathrm{H}=0$
d. $\Delta U=0$

Amita Prajapat

Numerade Educator

Problem 10

The enthalpy and entropy change for the reaction
$\mathrm{Br}_{2}$ (l) $+\mathrm{Cl}_{2}(\mathrm{~g}) \rightarrow 2 \mathrm{BrCl}(\mathrm{g})$
are $30 \mathrm{~kJ} \mathrm{~mol}^{-1}$ and $105 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}$ respectively.
The temperature at which the reaction will be in equilibrium is
a. $450 \mathrm{~K}$
b. $300 \mathrm{~K}$
c. $285.7 \mathrm{~K}$
d. $273 \mathrm{~K}$

Amita Prajapat

Numerade Educator

Problem 11

For a spontaneous process, the correct statement is
a. entropy of the system always increases
b. free energy of the system always increases
c. total entropy change is always negative
d. total entropy change is always positive

Mahipal Kumawat

Mahipal Kumawat

Numerade Educator

Problem 12

A heat engine absorbs heat $\mathrm{q}_{1}$ from a source at temperature $\mathrm{T}_{1}$ and heat $\mathrm{q}_{2}$ from a source at temperature $\mathrm{T}_{2}$. Work done is found to be $\mathrm{J}\left(\mathrm{q}_{1}+\mathrm{q}_{2}\right)$. This is in accordance with:
a. first law of thermodynamics
b. second law of thermodynamics
c. joules equivalent law
d. none of these

Mahipal Kumawat

Mahipal Kumawat

Numerade Educator

Problem 13

Identify the correct statement for change of Gibb's energy for a system $\left(\Delta \mathrm{G}_{\text {system }}\right)$ at constant temperature and pressure:
a. if $\Delta \mathrm{G}_{\text {system }}=0$, the system is still moving in a particular direction
b. if $\Delta \mathrm{G}_{\text {system }}=-\mathrm{ve}$, the process is not spontaneous
c. if $\Delta \mathrm{G}_{\text {system }}=+\mathrm{ve}$, the process is spontaneous
d. if $\Delta G_{s y s c m}=0$, the system has attained equilibrium

Amita Prajapat

Numerade Educator

Problem 14

For the reaction of one mole of $\mathrm{Zn}$-dust with one mole of $\mathrm{H}_{2} \mathrm{SO}_{4}$ in a bomb calorimeter, $\Delta \mathrm{U}$ an $\mathrm{W}$ corresponds to:
a. $\Delta \mathrm{U}<0, \mathrm{~W}=0$
b. $\Delta U<0, W<0$
c. $\Delta \mathrm{U}>0, \mathrm{~W}=0$
d. $\Delta U>0, W>0$

Amita Prajapat

Numerade Educator

Problem 15

$\Delta \mathrm{H}_{\mathrm{f}}^{\circ}(298)$ of methanol is given by chemical equation
a. $\mathrm{CH}_{4}(\mathrm{~g})+1 / 2 \mathrm{O}_{2}(\mathrm{~g}) \rightarrow \mathrm{CH}_{3} \mathrm{OH}(\mathrm{g})$
b. $\mathrm{CO}(\mathrm{g})+2 \mathrm{H}_{2}(\mathrm{~g}) \rightarrow \mathrm{CH}_{3} \mathrm{OH}$ (l)
c. $\mathrm{C}$ (graphite) $+1 / 2 \mathrm{O}_{2}(\mathrm{~g})+2 \mathrm{H}_{2}(\mathrm{~g}) \rightarrow \mathrm{CH}_{3} \mathrm{OH}$ (l)
d. $\mathrm{C}$ (diamond) $+1 / 2 \mathrm{O}_{2}(\mathrm{~g})+2 \mathrm{H}_{2}(\mathrm{~g}) \rightarrow \mathrm{CH}_{3} \mathrm{OH}$ (l)

Amita Prajapat

Numerade Educator

Problem 16

Assume each reaction is carried out in an open container. For which reaction will $\Delta \mathrm{H}=\Delta \mathrm{U}$ ?
a. $\mathrm{PCl}_{5}(\mathrm{~g}) \rightarrow \mathrm{PCl}_{3}(\mathrm{~g})+\mathrm{Cl}_{2}(\mathrm{~g})$
b. $2 \mathrm{CO}(\mathrm{g})+\mathrm{O}_{2}(\mathrm{~g}) \rightarrow 2 \mathrm{CO}_{2}(\mathrm{~g})$
c. $\mathrm{H}_{2}(\mathrm{~g})+\mathrm{Br}_{2}(\mathrm{~g}) \rightarrow 2 \mathrm{HBr}(\mathrm{g})$
d. $\mathrm{C}(\mathrm{s})+2 \mathrm{H}_{2} \mathrm{O}(\mathrm{g}) \rightarrow 2 \mathrm{H}_{2}(\mathrm{~g})+\mathrm{CO}_{2}(\mathrm{~g})$

Amita Prajapat

Numerade Educator

Problem 17

The absolute enthalpy of neutralization of the reaction
$\mathrm{MgO}(\mathrm{s})+2 \mathrm{HCl}(\mathrm{aq}) \rightarrow \mathrm{MgCl}_{2}(\mathrm{aq})+\mathrm{H}_{2} \mathrm{O}(\mathrm{l})$
will be
a. $-57.33 \mathrm{~kJ} /$ mole
b. $>-57.33 \mathrm{~kJ} / \mathrm{mole}$
c. $<-57.33 \mathrm{~kJ} / \mathrm{mole}$
d. $57.33 \mathrm{~kJ} /$ mole.

Hunza Gilgit

Numerade Educator

Problem 18

A reaction occurs spontaneously if
a. $\mathrm{T} \Delta \mathrm{S}<\Delta \mathrm{H}$ and both $\Delta \mathrm{H}, \Delta \mathrm{S}$ are $+\mathrm{ve}$
b. $\mathrm{T} \Delta \mathrm{S}>\Delta \mathrm{H}$ and $\Delta \mathrm{H}=+\mathrm{ve}, \Delta \mathrm{S}=-\mathrm{ve}$
c. $\mathrm{T} \Delta \mathrm{S}>\Delta \mathrm{H}$ and both $\Delta \mathrm{H}, \Delta \mathrm{S}$ are $+\mathrm{ve}$
d. $\mathrm{T} \Delta \mathrm{S}=\Delta \mathrm{H}$ and both $\Delta \mathrm{H}, \Delta \mathrm{S}$ are $+\mathrm{ve}$

Amita Prajapat

Numerade Educator

Problem 19

If at $298 \mathrm{~K}$ the bond energies of $\mathrm{C}-\mathrm{H}, \mathrm{C}-\mathrm{C}, \mathrm{C}=\mathrm{C}$
and $\mathrm{H}-\mathrm{H}$ bonds are respectively $414,347,615$ and $435 \mathrm{~kJ} \mathrm{~mol}^{-1}$, the value of enthalpy change for the reaction
$\mathrm{H}_{2} \mathrm{C}=\mathrm{CH}_{2}(\mathrm{~g})+\mathrm{H}_{2}(\mathrm{~g}) \rightarrow \mathrm{H}_{3} \mathrm{C}-\mathrm{CH}_{3}(\mathrm{~g})$
at $298 \mathrm{~K}$ will be
a. $+250 \mathrm{~kJ}$
b. $-250 \mathrm{~kJ}$
c. $+125 \mathrm{~kJ}$
d. $-125 \mathrm{~kJ}$

Mahipal Kumawat

Mahipal Kumawat

Numerade Educator

Problem 20

A gas expands into a vacuum (external pressure $=0$ ) while in thermal isolation from the surroundings. For this expansion
a. $\Delta \mathrm{E}$ does not change
b. $\Delta \mathrm{E}$ increases
c. $\Delta \mathrm{E}=\mathrm{T}^{1} \mathrm{~S}$
d. $\Delta \mathrm{E}$ decreases

Amita Prajapat

Numerade Educator

Problem 21

For a process at constant volume,
a. $\mathrm{w}=0$ and $\Delta \mathrm{E}=\Delta \mathrm{H}$
b. $\mathrm{w}=0$ and $\Delta \mathrm{H}=\mathrm{q}$
c. $\mathrm{q}=0, \mathrm{w}=0$ and $\Delta \mathrm{E}=0$
d. $\mathrm{w}=0$ and $\Delta \mathrm{E}=\mathrm{q}$

Amita Prajapat

Numerade Educator

Problem 22

In an irreversible process taking place at constant $\mathrm{T}$ and $\mathrm{P}$ and in which only pressure -volume work is being done, the change in Gibbs free energy $(\mathrm{dG})$ and change in entropy (dS), satisfy the criteria:
a. $(\mathrm{dS})_{\mathrm{V}, \mathrm{E}}<0,(\mathrm{dG})_{\mathrm{T}, \mathrm{P}}<0$
b. $(\mathrm{dS})_{\mathrm{V}, \mathrm{E}}>0,(\mathrm{~d} \mathrm{G})_{\mathrm{T}, \mathrm{P}}<0$
c. $(\mathrm{dS})_{\mathrm{V}, \mathrm{E}}=0,(\mathrm{dG})_{\mathrm{T}, \mathrm{P}}=0$
d. $(\mathrm{dS})_{\mathrm{V}, \mathrm{E}}=0,(\mathrm{dG})_{\mathrm{T}, \mathrm{P}}>0$

Amita Prajapat

Numerade Educator

Problem 23

Which of the following pairs of a chemical reaction is certain to result in a spontaneous reaction?
a. exothermic and increasing disorder
b. exothermic and decreasing disorder
c. endothermic and increasing disorder
d. endothermic and decreasing disorder

Amita Prajapat

Numerade Educator

Problem 24

The internal energy change when a system goes from state $\mathrm{A}$ to $\mathrm{B}$ is $40 \mathrm{~kJ} / \mathrm{mol}$. if the system goes from $\mathrm{A}$ to $\mathrm{B}$ by a reversible path and returns to state A by an irreversible path what would be the net change in internal energy?
a. $40 \mathrm{~kJ}$
b. $>40 \mathrm{~kJ}$
c. $<40 \mathrm{~kJ}$
d. zero

Amita Prajapat

Numerade Educator

Problem 25

Standard state Gibbs free energy change for isomerization reaction,
Cis-2-pentene $\leftrightarrow$ trans-2-pentene
is $-3.67 \mathrm{~kJ} / \mathrm{mol}$ at $400 \mathrm{~K}$. if more trans-2-pentene is added to the reaction vessel, then:
a. more cis-2-pentene is formed
b. additional trans-2-pentene is formed
c. equilibrium remains unaffected
d. equilibrium is shifted in the forward direction

Muhammad Ahsan

Numerade Educator

Problem 26

An ideal gas expands in volume from $1 \times 10^{-3} \mathrm{~m}^{3}$ to $1 \times 10^{-2} \mathrm{~m}^{3}$ at $300 \mathrm{~K}$ against a constant pressure of $1 \times 10^{5} \mathrm{Nm}^{-2}$. The work done is
a. $-900 \mathrm{~kJ}$
b. $-900 \mathrm{~J}$
c. $270 \mathrm{~kJ}$
d. $940 \mathrm{~kJ}$

Amita Prajapat

Numerade Educator

Problem 27

For a reaction to occur spontaneously
a. $(\Delta \mathrm{H}-\mathrm{T} \Delta \mathrm{S})$ must be negative
b. $(\Delta H+T \Delta S)$ must be negative
c. $\Delta \mathrm{H}$ must be negative
d. $\Delta \mathrm{S}$ must be negative

Amita Prajapat

Numerade Educator

Problem 28

Which one of the following has $\Delta \mathrm{S}^{\circ}$ greater than zero?
a. $\mathrm{CaO}(\mathrm{s})+\mathrm{CO}_{2}(\mathrm{~g}) \leftrightarrow \mathrm{CaCO}_{3}(\mathrm{~g})$
b. $\mathrm{NaCl}(\mathrm{aq}) \leftrightarrow \mathrm{NaCl}(\mathrm{s})$
c. $\mathrm{NaNO}_{3}(\mathrm{~s}) \leftrightarrow \mathrm{Na}^{+}(\mathrm{aq})+\mathrm{NO}_{3}^{-}(\mathrm{aq})$
d. $\mathrm{N}_{2}(\mathrm{~g})+3 \mathrm{H}_{2}(\mathrm{~g}) \leftrightarrow 2 \mathrm{NH}_{3}(\mathrm{~g})$

Amita Prajapat

Numerade Educator

Problem 29

For an explosion in an open vessel, one would expect
a. $\Delta \mathrm{H}$ to be negative and $\Delta \mathrm{E}$ to be greater than $\Delta \mathrm{H}$
b. $\Delta \mathrm{H}$ to be negative and $\Delta \mathrm{E}$ to be less than $\Delta \mathrm{H}$
c. $\Delta \mathrm{H}$ to be positive and $\Delta \mathrm{E}$ to be less than $\Delta \mathrm{H}$
d. $\Delta \mathrm{H}$ to be positive and $\Delta \mathrm{E}$ to be greater than $\Delta \mathrm{H}$

Amita Prajapat

Numerade Educator

Problem 30

Which of the following is correct equation?
a. $\Delta U=\Delta Q-W$
b. $\Delta W=\Delta U+\Delta Q$
c. $\Delta \mathrm{U}=\Delta \mathrm{W}+\Delta \mathrm{Q}$
d. none of these

Mahipal Kumawat

Mahipal Kumawat

Numerade Educator

Problem 31

Consider the reaction $\mathrm{N}_{2}+3 \mathrm{H}_{2} \leftrightarrow 2 \mathrm{NH}_{3}$ carried out at constant temperature and pressure. If $\Delta \mathrm{H}$ and $\Delta \mathrm{U}$ are the enthalpy and internal energy changes for the reaction. Which of the following expressions is true?
a. $\Delta \mathrm{H}=0$
b. $\Delta \mathrm{H}=\Delta \mathrm{U}$
c. $\Delta \mathrm{H}<\Delta \mathrm{U}$
d. $\Delta \mathrm{H}>\Delta \mathrm{U}$

Mahipal Kumawat

Mahipal Kumawat

Numerade Educator

Problem 32

$1 \mathrm{~mol}$ of an ideal gas at $300 \mathrm{~K}$ is expanded isothermally and reversible from an initial volume of 1 litre to 10 litre. The work in this process is $(\mathrm{R}=2$ $\mathrm{cal} \mathrm{mol}^{-1} \mathrm{~K}^{-1}$ )
a. $163.7 \mathrm{cal}$
b. zero
c. $-1381.8 \mathrm{cal}$
d. 9 litre atm

Amita Prajapat

Numerade Educator

Problem 33

Identify the correct statement regarding entropy.
a. At absolute zero temperature, entropy of a perfectly crystalline substance is taken to be zero
b. At absolute zero of temperature the entropy of a perfectly crystalline substance is $+v$ e
c. At absolute zero of temperature the entropy of all crystalline substance is to be zero
d. At $0^{\circ} \mathrm{C}$, the entropy of a perfectly crystalline substance is taken to be zero

Amita Prajapat

Numerade Educator

Problem 34

A gas expands against a non-zero external pressure while in thermal isolation from the surroundings. For this expansion
a. $\Delta \mathrm{E}=\mathrm{q}$
b. $\Delta \mathrm{E}$ increases
c. $\Delta \mathrm{E}$ does not change
d. $\Delta \mathrm{E}$ decreases

Amita Prajapat

Numerade Educator

Problem 35

The standard enthalpy of formation $\left(\Delta \mathrm{H}^{\circ}\right)$ at 298 $\mathrm{K}$ for methane, $\mathrm{CH}_{4}(\mathrm{~g})$ is $-74.8 \mathrm{~kJ} \mathrm{~mol}^{-1}$, the addi-
tional information required to determine the average energy for $\mathrm{C}-\mathrm{H}$ bond formation would be
a. the dissociation energy of $\mathrm{H}_{2}$ and enthalpy of sublimation of carbon
b. latent heat of vapourization of methane
c. the first four ionization energies of carbon and electron gain enthalpy of hydrogen
d. the dissociation energy of hydrogen molecule, $\mathrm{H}_{2}$

Amita Prajapat

Numerade Educator

Problem 36

The factor of $\Delta \mathrm{G}$ values is important in metallurgy. The $\Delta \mathrm{G}$ values for the following reactions at $800^{\circ} \mathrm{C}$ are given as
$\mathrm{S}_{2}(\mathrm{~s})+2 \mathrm{O}_{2}(\mathrm{~g}) \rightarrow 2 \mathrm{SO}_{2}(\mathrm{~g}) ; \Delta \mathrm{G}=-544 \mathrm{~kJ}$
$2 \mathrm{Zn}(\mathrm{s})+\mathrm{S}_{2}(\mathrm{~s}) \rightarrow 2 \mathrm{ZnS}(\mathrm{s}) ; \Delta \mathrm{G}=-293 \mathrm{~kJ}$
$2 \mathrm{Zn}(\mathrm{s})+\mathrm{O}_{2}(\mathrm{~g}) \rightarrow 2 \mathrm{ZnO}(\mathrm{s}) ; \Delta \mathrm{G}=-480 \mathrm{~kJ}$
the $\Delta \mathrm{G}$ for the reaction, $2 \mathrm{ZnS}(\mathrm{s})+3 \mathrm{O}_{2}(\mathrm{~g}) \rightarrow 2 \mathrm{ZnO}(\mathrm{s})+2 \mathrm{SO}_{2}(\mathrm{~g})$
will be
a. $-357 \mathrm{~kJ}$
b. $-731 \mathrm{~kJ}$
c. $-773 \mathrm{~kJ}$
d. $-229 \mathrm{~kJ}$

Mahipal Kumawat

Mahipal Kumawat

Numerade Educator

Problem 37

An ideal gas is allowed to expand both reversibly and irreversibly in an isolated system. If $\mathrm{Ti}$ is the initial temperature and $\mathrm{T}_{\mathrm{f}}$ is the final temperature, which of the following statements is correct?
a. $\left(T_{i}\right)_{i m e v}>\left(T_{F}\right)_{r e v}$
b. $\mathrm{T}_{\mathrm{f}}>\mathrm{T}_{\mathrm{i}}$ for reversible process but $\mathrm{T}_{\mathrm{f}}=\mathrm{T}_{\mathrm{i}}$ for
irreversible process
c. $\left(T_{f}\right)$ irrev $=\left(T_{F}\right) r e v$
d. $\mathrm{T}_{\mathrm{f}}=\mathrm{T}_{\mathrm{i}}$ for both reversible and irreversible processes

Amita Prajapat

Numerade Educator

Problem 38

The entropy change in the fusion of $1 \mathrm{~mol}$ of a solid melting at $27^{\circ} \mathrm{C}$ (Latent heat of fusion, $2930 \mathrm{~J} \mathrm{~mol}^{-1}$ ) is
a. $9.77 \mathrm{JK}^{-1} \mathrm{~mol}^{-1}$
b. $10.73 \mathrm{JK}^{-1} \mathrm{~mol}^{-1}$
c. $2930 \mathrm{JK}^{-1} \mathrm{~mol}^{-1}$
d. $108.5 \mathrm{JK}^{-1} \mathrm{~mol}^{-1}$

Amita Prajapat

Numerade Educator

Problem 39

As a given temperature and pressure, which of the following would be expected to have the greatest molar entropy?
a. $\mathrm{Br}_{2}(\mathrm{~g})$
b. $\mathrm{Br}_{2}(\mathrm{~s})$
c. $\mathrm{Br}_{2}$ (I)
d. All of these would be expected to have the same molar entropy.

Amita Prajapat

Numerade Educator

Problem 40

The standard enthalpy of formation $\left(\Delta_{t} \mathrm{H}^{\circ}\right)$ at 298 $\mathrm{K}$ for methane, $\mathrm{CH}_{4}(\mathrm{~g})$ is $-74.8 \mathrm{~kJ} \mathrm{~mol}^{-1}$. the addi-
tional information required to determine the average energy for $\mathrm{C}-\mathrm{H}$ bond formation would be
a. the dissociation energy of $\mathrm{H}_{2}$ and enthalpy of sublimation of carbon
b. latent heat of vapourization of methane
c. the first four ionization energies of carbon and electron gain enthalpy of hydrogen
d. the dissociation energy of hydrogen molecule, $\mathrm{H}_{2}$

Amita Prajapat

Numerade Educator

Problem 41

When $1 \mathrm{~mol}$ gas is heated at constant volume temperature is raised from 298 to $308 \mathrm{~K}$. Heat supplied to the gas is $500 \mathrm{~J}$. Then which statement is correct?
a. $\mathrm{q}=\mathrm{W}=500 \mathrm{~J}, \Delta \mathrm{U}=0$
b. $\mathrm{q}=\Delta \mathrm{U}=500 \mathrm{~J}, \mathrm{~W}=0$
c. $q=W=500 \mathrm{~J}, \Delta U=0$
d. $\Delta \mathrm{U}=0, \mathrm{q}=$

Amita Prajapat

Numerade Educator

Problem 42

For the reaction:
$\mathrm{S}_{8}(\mathrm{~s})+8 \mathrm{O}_{2}(\mathrm{~g}) \rightarrow 8 \mathrm{SO}_{2}(\mathrm{~g})$
a. $\Delta \mathrm{H}<\Delta \mathrm{E}$
b. $\Delta \mathrm{H}=\Delta \mathrm{E}$
c. $\Delta \mathrm{H}>\Delta \mathrm{E}$
d. $\Delta \mathrm{H}$ is independent of the physical state of reactants.

Amita Prajapat

Numerade Educator

Problem 43

$2 \mathrm{~mol}$ of an ideal gas at $27^{\circ} \mathrm{C}$ temperature is expanded reversibly from $2 \mathrm{~L}$ to $20 \mathrm{~L}$. Find entropy change in cal. $(\mathrm{R}=2 \mathrm{cal} / \mathrm{mol} \mathrm{K})$
a. $92.1$
b. 0
c. 4
d. $9.2$

Amita Prajapat

Numerade Educator

Problem 44

$(\Delta H-\Delta U)$ for the formation of carbon monoxide (CO) from its elements at $298 \mathrm{~K}$ is
a. $-1238.78 \mathrm{~J} \mathrm{~mol}^{-1}$
b. $1238.78 \mathrm{~J} \mathrm{~mol}^{-1}$
c. $-2477.57 \mathrm{~J} \mathrm{~mol}^{-1}$
d. $2477.57 \mathrm{~J} \mathrm{~mol}^{-1}$

Mahipal Kumawat

Mahipal Kumawat

Numerade Educator

Problem 45

For the reaction, $\mathrm{C}_{3} \mathrm{H}_{8}(\mathrm{~g})+5 \mathrm{O}_{2}(\mathrm{~g}) \rightarrow 3 \mathrm{CO}_{2}(\mathrm{~g})+4 \mathrm{H}_{2} \mathrm{O}(l)$
at constant temperature, $\Delta \mathrm{H}-\Delta \mathrm{E}$ is
a. $+3 \mathrm{RT}$
b. $-\mathrm{RT}$
c. $+\mathrm{RT}$
d. $-3 \mathrm{RT}$

Amita Prajapat

Numerade Educator

Problem 46

What is the entropy change (in $\mathrm{JK}^{-1} \mathrm{~mol}^{-1}$ ) when 1 mol of ice is converted into water at $0^{\circ} \mathrm{C}$ ? (The enthalpy change for the conversion of ice to liquid water is $6.0 \mathrm{~kJ} \mathrm{~mol}^{-1}$ at $0^{\circ} \mathrm{C}$ )
a. $2.198$
b. $21.98$
c. $20.13$
d. $2.013$

Amita Prajapat

Numerade Educator

Problem 47

An ideal gas expand against a constant external pressure of $5.0$ atmosphere from 40 to 60 litre and absorb $40 \mathrm{~kJ}$ of energy from surrounding. The change in internal energy of the system will be
a. $20.52 \mathrm{~kJ}$
b. $52.75 \mathrm{~kJ}$
c. $32.75 \mathrm{~kJ}$
d. $35.95 \mathrm{~kJ}$

Amita Prajapat

Numerade Educator

Problem 48

The molar heat capacity of water at constant pressure, $\mathrm{C}$, is $75 \mathrm{JK}^{-1} \mathrm{~mol}^{-1}$. When $1.0 \mathrm{~kJ}$ of heat is supplied to $100 \mathrm{~g}$ of water which is free to expand, the increase in temperature of water is
a. $4.8 \mathrm{~K}$
b. $6.6 \mathrm{~K}$
c. $1.2 \mathrm{~K}$
d. $2.4 \mathrm{~K}$

Amita Prajapat

Numerade Educator

Problem 49

The incorrect statement amongst the following is
a. at equilibrium $\Delta \mathrm{H}_{\mathrm{s}, \mathrm{P}}=0$
b. the condition of equilibrium at constant $\mathrm{P}$ and $\mathrm{T}$ is that $\mathrm{G}$ must be minimum
c. at equilibrium $\Delta \mathrm{G}_{\mathrm{p}, \mathrm{T}}=0$
d. $\Delta \mathrm{G}^{\circ}$ calculated using the equation; $\Delta \mathrm{G}^{\circ}=-\mathrm{RT}$ In $\mathrm{Kp}$, is the free energy change of the reaction when each of the species (reactants and products) is in the standard state of unit activity that is, roughly unit concentration.

Hunza Gilgit

Numerade Educator

Problem 50

The heat liberated on complete combustion of $7.8$ gm of benzene is $327 \mathrm{~kJ}$. This heat was measured at constant volume and at $27^{\circ} \mathrm{C}$. Calculate the heat of combustion of benzene at constant pressure $(\mathrm{R}=8.3 \mathrm{~J} / \mathrm{mole} / \mathrm{K})$
a. $-1637 \mathrm{~kJ} / \mathrm{mole}$
b. $-3274 \mathrm{~kJ} / \mathrm{mole}$
c. $-3270 \mathrm{~kJ} / \mathrm{mole}$
d. none of these

Amita Prajapat

Numerade Educator

Problem 51

$\mathrm{AB}, \mathrm{A}_{2}$ and $\mathrm{B}_{2}$ are diatomic molecule if the bond enthalpies of $\mathrm{A}_{2}, \mathrm{AB}$ and $\mathrm{B}_{2}$ are in the ratio $1: 1: 0.5$ and the enthalpy of formation of $\mathrm{AB}$ from $\mathrm{A}$ and $\mathrm{B}_{2}$ is $100 \mathrm{~kJ} / \mathrm{mole}$. What is the bond enthalpy of $\mathrm{A}_{2}$ ?
a. $400 \mathrm{~kJ} / \mathrm{mole}$
b. $300 \mathrm{~kJ} / \mathrm{mole}$
c. $200 \mathrm{~kJ} / \mathrm{mole}$
d. $100 \mathrm{~kJ} / \mathrm{mole}$

Hunza Gilgit

Numerade Educator

Problem 52

Considering entropy (S) as a thermodynamic parameter, the criterion for the spontaneity of any process is
a. $\Delta \mathrm{S}_{\text {sysem }}+\Delta \mathrm{S}_{\text {surroundings }}>0$
b. $\Delta \mathrm{S}_{\text {system }}-\Delta \mathrm{S}_{\text {surroundings }}>0$
c. $\Delta S_{\text {system }}>0$ only
d. $\Delta \mathrm{S}_{\text {surrondings }}>0$ only

Amita Prajapat

Numerade Educator

Problem 53

The gas in a refrigerator causes cooling on expansion because
a. work done by the gas is converted into heat
b. heat of the gas is lost as work is done by the gas
c. the heat is spread over a larger space
d. None

Amita Prajapat

Numerade Educator

Problem 54

The standard heats of formation of $\mathrm{NO}_{2}(\mathrm{~g})$ and $\mathrm{N}_{2} \mathrm{O}_{4}(\mathrm{~g})$ are $8.0$ and $2.0 \mathrm{kcal} \mathrm{mol}^{-1}$ respectively.
The heat of dimerization of $\mathrm{NO}_{2}$ in kcal is
a. $10.0$
b. $-6.0$
c. $-12.0$
d. $-14.0$

Amita Prajapat

Numerade Educator

Problem 55

Calculate the work done during isothermal expansion of one mole of an ideal gas from 10 atm to atm at $300 \mathrm{~K}$.
a. $-1382$ cal
b. $-1382$ joule
c. $-13.82 \mathrm{cal}$
d. $-1.382 \mathrm{cal}$

Amita Prajapat

Numerade Educator

Problem 56

The heats of neutralization of four acids $\mathrm{a}, \mathrm{b}, \mathrm{c}$ and $\mathrm{d}$ when neutralized against a common base and $13.7,9.4,11.2$ and $12.4 \mathrm{kcal}$ respectively. the weakest among these acids is
a. a
b. b
c. $\mathrm{c}$
d. d

Hunza Gilgit

Numerade Educator

Problem 57

Which of the following salts shall cause maximum cooling when one mole of the salt is dissolved in the same amount of water? (integral heat of solution at $298 \mathrm{~K}$ is given for each solute)
a. $\mathrm{KNO}_{3}, \Delta \mathrm{H}=35.4 \mathrm{~kJ}$ mol-
b. $\mathrm{NaCl}, \Delta \mathrm{H}=-5.35 \mathrm{~kJ} \mathrm{~mol}^{-}$
c. $\mathrm{KOH}, \Delta \mathrm{H}=-55.6 \mathrm{~kJ} \mathrm{~mol}-$
d. $\mathrm{KBr}, \Delta \mathrm{H}=-83.3 \mathrm{~kJ} \mathrm{~mol}^{-}$

Amita Prajapat

Numerade Educator

Problem 58

The melting point of a solid is $27^{\circ} \mathrm{C}$ and it's latent heat of fusion is 600 calories per mole. The entropy change for the fusion of one mole of the solid (in $\mathrm{cal} \mathrm{K}^{-1}$ ) is
a. 180
b. $22.2$
c. 2
d. $0.5$

Hunza Gilgit

Numerade Educator

Problem 59

Devitrification of glass is a process for which change in entropy $(\Delta \mathrm{S})$
a. $-v e$
b. $+v e$
c. 0
d. $\Delta \mathrm{S}$ value depend on the nature of glass

Amita Prajapat

Numerade Educator

Problem 60

In a flask, colourless $\mathrm{N}_{2} \mathrm{O}_{4}$ is in equilibrium with brown coloured $\mathrm{NO}_{2}$. At equilibrium, the brown colour deepens on heating the flask to $100^{\circ} \mathrm{C}$ and on cooling it become less coloured. $\Delta \mathrm{H}$ for the system is
a. positive
b. negative
c. zero
d. undefined

Hunza Gilgit

Numerade Educator

Problem 61

Which of the following modes of energy constitute both kinetic and potential energy?
a. nuclear energy
b. transitional energy
c. rotational energy
d. vibrational energy

Hunza Gilgit

Numerade Educator

Problem 62

Which of the following is not expected to be correct?
a. $\Delta \mathrm{H}_{\mathrm{f}}^{\mathrm{o}}\left(\mathrm{CO}_{2}\right)=$ negative
b. $\Delta \mathrm{H}_{\text {camb }}(\mathrm{NO})=$ positive
c. $\Delta \mathrm{H}_{\mathrm{hyd}}\left(\mathrm{BaCl}_{2}\right)=$ negative
d. $\Delta \mathrm{H}_{\text {neut }}=$ negative

Amita Prajapat

Numerade Educator

Problem 63

The standard heat of formation of diamond is
a. same as that of graphite
b. greater than that of graphite
c. less than that of graphite
d. taken as zero

Hunza Gilgit

Numerade Educator

Problem 64

How many calories are required to heat 40 gram of argon from 40 to $100^{\circ} \mathrm{C}$ at constant volume? $(\mathrm{R}=2 \mathrm{cal} / \mathrm{mol} . \mathrm{K})$
a. 120
b. 180
c. 1800
d. 2400

Amita Prajapat

Numerade Educator

Problem 65

Which of the following does not express criterion of spontaneity?
a. $(\mathrm{dS})_{\mathrm{PT}}>0$
b. $(\mathrm{dA})_{\mathrm{VT}} \geq 0$
c. $(\mathrm{dG})_{\mathrm{PT}}<0$
d. All of these

Hunza Gilgit

Numerade Educator

Problem 66

Which one of the following set of units represents the smallest and the largest amount of energy respectively?
a. $\mathrm{eV}$ and lit atm
b. $\mathrm{Cal}$ and $\mathrm{eV}$
c. $\mathrm{J}$ and erg
d. erg and cal

Amita Prajapat

Numerade Educator

Problem 67

If $K<1.0$, what will be the value of $\Delta G^{\circ}$ of the following?
a. Zero
b. Negative
c. Positive
d. $1.0$

Amita Prajapat

Numerade Educator

Problem 68

Which of the following are not state functions?
(I) $\mathrm{q}+\mathrm{w}$
(II) q
(III) W
(IV) $\mathrm{H}-\mathrm{TS}$
a. (I), (II) and (III)
b. (II) and (III)
c. (I) and (IV)
d. (II), (III) and (IV)

Amita Prajapat

Numerade Educator

Problem 69

Oxidizing power of chlorine in aqueous solution can be determined by the parameters indicated below:
$1 / 2 \mathrm{Cl}_{2}(\mathrm{~g}) \stackrel{1 / 2 \Delta_{\mathrm{diss}} \mathrm{H}^{-}}{\longrightarrow} \mathrm{Cl}(\mathrm{g}) \stackrel{\Delta_{\mathrm{eg}} \mathrm{H}^{-}}{\longrightarrow}$
$\mathrm{Cl}^{-}(\mathrm{g}) \stackrel{\Delta_{\text {hyd. }} \mathrm{H}^{-}}{\longrightarrow} \mathrm{Cl}^{-}(\mathrm{aq})$
The energy involved in the conversion of $1 / 2 \mathrm{Cl}_{2}(\mathrm{~g})$ to $\mathrm{Cl}^{-}(\mathrm{g})$
(Using the data, $\Delta_{\text {diss }} \mathrm{H} \mathrm{Cl}_{2}=240 \mathrm{~kJ} \mathrm{~mol}^{-1}, \Delta_{\mathrm{cg}} \mathrm{H} \mathrm{Cl}$
$\left.=-349 \mathrm{~kJ} \mathrm{~mol}^{-1}, \Delta_{\mathrm{hyd}} \mathrm{H}-\mathrm{Cl}=-381 \mathrm{~kJ} \mathrm{~mol}^{-1}\right)$
will be
a. $+152 \mathrm{~kJ} \mathrm{~mol}^{-1}$
b. $-610 \mathrm{~kJ} \mathrm{~mol}^{-1}$
c. $-850 \mathrm{~kJ} \mathrm{~mol}^{-1}$
d. $+120 \mathrm{~kJ} \mathrm{~mol}^{-1}$

Himanshu Kushwaha

Himanshu Kushwaha

Numerade Educator

Problem 70

For the gas phase reaction, $\mathrm{PCl}_{5}(\mathrm{~g}) \rightleftharpoons \mathrm{PCl}_{3}(\mathrm{~g})+\mathrm{Cl}_{2}(\mathrm{~g})$
Which of the following conditions are correct?
a. $\Delta \mathrm{H}<0$ and $\Delta \mathrm{S}<0$
b. $\Delta \mathrm{H}>0$ and $\Delta \mathrm{S}<0$
c. $\Delta \mathrm{H}=0$ and $\Delta \mathrm{S}<0$
d. $\Delta \mathrm{H}>0$ and $\Delta \mathrm{S}>0$

Amita Prajapat

Numerade Educator

Problem 71

Using the following thermochemical equations
(i) $\mathrm{S}_{\text {(th) }}+3 / 2 \mathrm{O}_{2(\mathrm{~g})} \rightarrow \mathrm{SO}_{3(\mathrm{~g})} ; \Delta \mathrm{H}=-2 \mathrm{x} \mathrm{kJ} \mathrm{mol}^{-1}$
(ii) $\mathrm{SO}_{2(\mathrm{~g})}+1 / 2 \mathrm{O}_{2(\mathrm{~g})} \rightarrow \mathrm{SO}_{3(\mathrm{gg}} ; \Delta \mathrm{H}=-\mathrm{y} \mathrm{kj} \mathrm{mol}^{-1}$
Find out the heat of formation of $\mathrm{SO}_{2(\mathrm{~g})}$ in $\mathrm{kJ} \mathrm{mol}^{-1} .$
a. $(x+y)$
b. $(2 x+y)$
c. $(2 \mathrm{x} / \mathrm{y})$
d. $(\mathrm{y}-2 \mathrm{x})$
e. $(2 x-y)$

Amita Prajapat

Numerade Educator

Problem 72

When compared to $\Delta \mathrm{G}^{\mathrm{o}}$ for the formation of $\mathrm{Al}_{2} \mathrm{O}_{3}$, the $\Delta \mathrm{G}^{\circ}$ for the formation of $\mathrm{Cr}_{2} \mathrm{O}_{3}$ is
a. Lower
b. Unpredicted
c. Higher
d. Same

Hunza Gilgit

Numerade Educator

Problem 73

For one mole of ammonia and one mole of hydrogen chloride are mixed in a closed container to form ammonium chloride gas, then
a. $\Delta \mathrm{H}=\Delta \mathrm{U}$
b. $\Delta \mathrm{H}<\Delta \mathrm{U}$
c. There is no relationship
d. $\Delta \mathrm{H}>\Delta$ UAn $\mathrm{s}=(\mathrm{A})$

Amita Prajapat

Numerade Educator

Problem 74

At a given pressure and volume, in the $\mathrm{P}-\mathrm{V}$ plot, of an ideal gas,
$\frac{\text { Slope of an adiabatic curve }}{\text { Slope of an isothermal curve }}$ is
a. $\mathrm{C}_{\mathrm{p}} / \mathrm{R}$
b. $\mathrm{C}_{\mathrm{V}} / \mathrm{C}_{\mathrm{p}}$
c. $\mathrm{C}_{\mathrm{p}} \mathrm{C}_{\mathrm{v}}$
d. $\mathrm{R}$

Hunza Gilgit

Numerade Educator

Problem 75

Enthalpy is equal to
a. $-\mathrm{T}^{2}[\partial(\mathrm{G} / \mathrm{T}) / \partial \mathrm{T}]_{\mathrm{V}}$
b. $\mathrm{T}^{2}[\hat{\partial}(\mathrm{G} / \mathrm{T}) / \partial \mathrm{T}]_{\mathrm{V}}$
c. $-\mathrm{T}^{2}[\hat{\partial}(\mathrm{G} / \mathrm{T}) / \partial \mathrm{T}]_{\mathrm{p}}$
d. $\mathrm{T}^{2}[\partial(\mathrm{G} / \mathrm{T}) / \partial \mathrm{T}]_{\mathrm{p}}$

Hunza Gilgit

Numerade Educator

Problem 76

The standard molar enthalpies of formation of cyclohexane (1) and benzene (l) at $25^{\circ} \mathrm{C}$ are156 and $+49 \mathrm{~kJ} \mathrm{~mol}^{-1}$ respectively. The standard enthalpy of hydrogenation of Cyclohexene (1) at $25^{\circ} \mathrm{C}$ is $-119 \mathrm{~kJ} / \mathrm{mol}$. Find resonance energy of benzene.
a. $-152 \mathrm{~kJ} \mathrm{~mol}^{-1}$
b. $-159 \mathrm{~kJ} \mathrm{~mol}^{-1}$
c. $+152 \mathrm{~kJ} \mathrm{~mol}^{-1}$
d. $+159 \mathrm{~kJ} \mathrm{~mol}^{-1}$

Hunza Gilgit

Numerade Educator

Problem 77

$0.50 \mathrm{~mol}$ of ammonium nitrate is added to $50.0 \mathrm{~mL}$ or water in a thermally insulated reaction vessel. Both are initially at $20.0^{\circ} \mathrm{C}$. After stirring the temperature of the solution is found to be less than $10^{\circ} \mathrm{C}$. Which statement best explains the temperature change?
a. Heat is evolved from the system to the surroundings.
b. Heat is absorbed from the surroundings by the system.
c. Heat is absorbed by ammonium nitrate when it dissolves and becomes hydrated.
d. Heat is evolved by ammonium nitrate when it dissolves and becomes hydrated.
e. The heat energy of the hydrated ions is less than the ions in solid ammonium nitrate.

Hunza Gilgit

Numerade Educator

Problem 78

Determine the sign of $\Delta \mathrm{S}^{\circ}$ for each of the following processes:
(I) $\mathrm{C}_{6} \mathrm{H}_{6}(\mathrm{~s}) \rightarrow \mathrm{C}_{6} \mathrm{H}_{6}(l)$
(II) $2 \mathrm{SO}_{2}(\mathrm{~g})+\mathrm{O}_{2}(\mathrm{~g}) \rightarrow 2 \mathrm{SO}_{3}(\mathrm{~g})$
a. $\Delta \mathrm{S}^{\circ}$ should be positive for I and positive for II.
b. $\Delta \mathrm{S}^{\circ}$ should be positive for I and negative for II
c. $\Delta \mathrm{S}^{\circ}$ should be negative for I and negative for II.
d. $\Delta \mathrm{S}^{\circ}$ should be negative for I and positive for II.

Hunza Gilgit

Numerade Educator

Problem 79

The difference between heats of reaction at constant pressure and constant volume for the reaction
$2 \mathrm{C}_{6} \mathrm{H}_{6}(l)+15 \mathrm{O}_{2}(\mathrm{~g}) \rightarrow 12 \mathrm{CO}_{2}(\mathrm{~g})+6 \mathrm{H}_{2} \mathrm{O}(l)$
at $25^{\circ} \mathrm{C}$ in $\mathrm{kJ}$ is
a. $-7.43$
b. $+3.72$
c. $-3.72$
d. $+7.43$

Amita Prajapat

Numerade Educator

Problem 80

$100 \mathrm{ml}$ of $0.3 \mathrm{M} \mathrm{HCl}$ solution is mixed with 100 $\mathrm{ml}$ of $0.33 \mathrm{M}$ KOH solution. The amount of heat liberated is
a. $1.713 \mathrm{~kJ}$
b. $17.42 \mathrm{~kJ}$
c. $1.31 \mathrm{~kJ}$
d. $17.13 \mathrm{~kJ}$

Hunza Gilgit

Numerade Educator

Problem 81

An athlete is given $100 \mathrm{~g}$ of glucose of energy equivalent to $1560 \mathrm{~kJ}$. He utilizes $50 \%$ of this gained energy in the event. In order to avoid storage of energy in the body, calculate the mass of water he would need to perspire. Enthalpy of $\mathrm{H}_{2} \mathrm{O}$ for evaporation is $44 \mathrm{~kJ} \mathrm{~mol}^{-1}$.
a. $346 \mathrm{~g}$
b. $316 \mathrm{~g}$
c. $323 \mathrm{~g}$
d. $319 \mathrm{~g}$

Mahipal Kumawat

Mahipal Kumawat

Numerade Educator

Problem 82

The enthalpies of formation of $\mathrm{CO}_{2}$ (g) and $\mathrm{CO}$ (g) at $298 \mathrm{~K}$ are in the ratio $2.56: 1$. For the reaction,
$\mathrm{CO}_{2}(\mathrm{~g})+\mathrm{C}(\mathrm{s}) \rightarrow$
$\mathrm{CO}(\mathrm{g}), \Delta \mathrm{H}=177.5 \mathrm{~kJ}, \Delta \mathrm{H}_{\mathrm{f}}$ of $\mathrm{CO}(\mathrm{g})$ is
a. $-113.78 \mathrm{~kJ} \mathrm{~mol}^{-1}$
b. $113.78 \mathrm{~kJ} \mathrm{~mol}^{-1}$
c. $-141.6 \mathrm{~kJ} \mathrm{~mol}^{-1}$
d. $-180.6 \mathrm{~kJ} \mathrm{~mol}^{-1}$

Hunza Gilgit

Numerade Educator

Problem 83

If for a given substance, $\mathrm{T}_{\mathrm{B}}$ is the m.p. and $\mathrm{T}_{\mathrm{A}}$ is the freezing point, then correct variation of entropy by graph between entropy change $(\Delta S)$ and temperature is

Himanshu Kushwaha

Himanshu Kushwaha

Numerade Educator

Problem 84

The standard enthalpy of combustion at $25^{\circ} \mathrm{C}$ of $\mathrm{H}_{2}, \mathrm{C}_{6} \mathrm{H}_{10}$ and cyclohexane $\left(\mathrm{C}_{6} \mathrm{H}_{12}\right)$ are $-241,-3800$
and $-3920 \mathrm{~kJ} \mathrm{~mol}^{-1}$ respectively. Calculate heat of hydrogenation of cyclohexane $\left(\mathrm{C}_{6} \mathrm{H}_{10}\right)$
a. $-161 \mathrm{~kJ} \mathrm{~mol}^{-1}$
b. $-131 \mathrm{~kJ} \mathrm{~mol}^{-1}$
c. $-121 \mathrm{~kJ} \mathrm{~mol}^{-1}$
d. None

Mahipal Kumawat

Mahipal Kumawat

Numerade Educator

Problem 85

Classify each of the following processes as spontaneous or non spontaneous.
I. $\mathrm{H}_{2} \mathrm{O}$ (l) $\rightarrow \mathrm{H}_{2} \mathrm{O}(\mathrm{g}) \mathrm{T}=25^{\circ} \mathrm{C}$ vessel open to atmo-
sphere with $50 \%$ relative humidity.
II. $\mathrm{H}_{2} \mathrm{O}(\mathrm{s}) \rightarrow \mathrm{H}_{2} \mathrm{O}$ (l) $\mathrm{T}=25^{\circ} \mathrm{C}, \mathrm{P}=1 \mathrm{~atm}$
a. I and II are both non spontaneous
b. I and II are both spontaneous
c. I is non spontaneous and II is spontaneous
d. I is spontaneous and II is non spontaneous.

Hunza Gilgit

Numerade Educator

Problem 86

The standard heats of formation of $\mathrm{CH}_{4}(\mathrm{~g}), \mathrm{CO}_{2}$
(g) and $\mathrm{H}_{2} \mathrm{O}(\mathrm{g})$ are $-76.2,-394.8$ and $-241.6 \mathrm{~kJ}$
$\mathrm{mol}^{-1}$ respectively. Calculate the amount of heat evolved by burning $1 \mathrm{~m}^{3}$ methane measured under normal conditions.
a. $162897.3 \mathrm{~kJ}$
b. $64078.2 \mathrm{~kJ}$
c. $35182 \mathrm{~kJ}$
d. none

Mahipal Kumawat

Mahipal Kumawat

Numerade Educator

Problem 87

For an explosion in an open vessel, one would expect
a. $\Delta \mathrm{H}$ to be negative and $\Delta \mathrm{E}$ to be greater than $\Delta \mathrm{H}$
b. $\Delta \mathrm{H}$ to be negative and $\Delta \mathrm{E}$ to be less than $\Delta \mathrm{H}$
c. $\Delta \mathrm{H}$ to be positive and $\Delta \mathrm{E}$ to be less than $\Delta \mathrm{H}$
d. $\Delta \mathrm{H}$ to be positive and $\Delta \mathrm{E}$ to be greater than $\Delta \mathrm{H}$

Hunza Gilgit

Numerade Educator

Problem 88

Calculate the resonance energy of $\mathrm{N}_{2} \mathrm{O}$ from the following data: $\Delta \mathrm{H}_{f}$ of $\mathrm{N}_{2} \mathrm{O}=82 \mathrm{~kJ} \mathrm{~mol}^{-1} .$ Bond
energies of $\mathrm{N} \equiv \mathrm{N}, \mathrm{N}=\mathrm{N}, \mathrm{O}=\mathrm{O}$ and $\mathrm{N}=\mathrm{O}$ bonds
are $946,418,498$ and $607 \mathrm{~kJ} \mathrm{~mol}^{-1}$ respectively.
a. $-88 \mathrm{~kJ} \mathrm{~mol}^{-1}$
b. $-170 \mathrm{~kJ} \mathrm{~mol}^{-1}$
c. $-82 \mathrm{~kJ} \mathrm{~mol}^{-1}$
d. $-258 \mathrm{~kJ} \mathrm{~mol}^{-1}$

Hunza Gilgit

Numerade Educator

Problem 89

The enthalpy changes for the following processes are listed below
$\mathrm{Cl}_{2}(\mathrm{~g})=2 \mathrm{Cl}(\mathrm{g}) \quad ; 242.3 \mathrm{~kJ} \mathrm{~mol}^{-1}$
$\mathrm{I}_{2}(\mathrm{~g})=2 \mathrm{I}(\mathrm{g}) \quad ; 151.0 \mathrm{~kJ} \mathrm{~mol}^{-1}$
$\mathrm{ICl}(\mathrm{g})=\mathrm{I}(\mathrm{g})+\mathrm{Cl}(\mathrm{g}) \quad ; 211.3 \mathrm{~kJ} \mathrm{~mol}^{-1}$
$\mathrm{I}_{2}(\mathrm{~s})=\mathrm{I}_{2}(\mathrm{~g})$
$; 62.76 \mathrm{~kJ} \mathrm{~mol}^{-1}$
Given that the standard states for iodine and chlorine are $\mathrm{I}_{2}$ (s) and $\mathrm{Cl}_{2}(\mathrm{~g})$, the standard enthalpy of formation for $\mathrm{ICl}(\mathrm{g})$ is
a. $-14.6 \mathrm{~kJ} \mathrm{~mol}^{-1}$
b. $-16.8 \mathrm{~kJ} \mathrm{~mol}^{-1}$
c. $+16.8 \mathrm{~kJ} \mathrm{~mol}^{-1}$
d. $+244.8 \mathrm{~kJ} \mathrm{~mol}^{-1}$

Hunza Gilgit

Numerade Educator

Problem 90

The following curve represents the variation of Gibbs function 'G' with pressure at constant temperature.
Correct match of given plots with the physical state of a substance is
a. I - solid, III- gas, II - liquid
b. I - gas, II - liquid, III - solid
c. I - liquid, II - solid, III - gas
d. III - gas, II - solid, I - liquid

Hunza Gilgit

Numerade Educator

Problem 91

Which of the following is in accord with the three laws of thermodynamics?
(I) The entropy of the universe never decreases.
(II) A non-spontaneous process can occur if it is coupled to a process that is sufficiently spontaneous.
a. I is true and II is false.
b. I is false and II is true.
c. Both I and II are true.
d. Both I and II are false.

Hunza Gilgit

Numerade Educator

Problem 92

Which of $\mathrm{CH}_{4}$ (g), $\mathrm{C}_{2} \mathrm{H}_{2}(\mathrm{~g})$ and $\mathrm{CH}_{3} \mathrm{OH}$ (I) provides the most energy per gram upon combustion and which provides the least?
$$
\begin{array}{r}
\mathrm{CH}_{4}(\mathrm{~g})+2 \mathrm{O}_{2}(\mathrm{~g}) \rightarrow \mathrm{CO}_{2}(\mathrm{~g})+2 \mathrm{H}_{2} \mathrm{O}(l) \\
\Delta \mathrm{H}^{\circ}=-890 \mathrm{~kJ}
\end{array}
$$
$2 \mathrm{C}_{2} \mathrm{H}_{2}(\mathrm{~g})+5 \mathrm{O}_{2}(\mathrm{~g}) \rightarrow 4 \mathrm{CO}_{2}(\mathrm{~g})+2 \mathrm{H}_{2} \mathrm{O}(l)$
$$
\Delta \mathrm{H}^{\circ}=-2599 \mathrm{~kJ}
$$
$2 \mathrm{CH}_{3} \mathrm{OH}(\mathrm{l})+3 \mathrm{O}_{2}(\mathrm{~g}) \rightarrow 2 \mathrm{CO}_{2}(\mathrm{~g})+4 \mathrm{H}_{2} \mathrm{O}(l)$
$$
\Delta \mathrm{H}^{\circ}=-1453 \mathrm{~kJ}
$$
a. $\mathrm{C}_{2} \mathrm{H}_{2}$ provides the most energy per gram and $\mathrm{CH}_{3} \mathrm{OH}$ the least.
b. $\mathrm{C}_{2} \mathrm{H}_{2}$ provides the most energy per gram and $\mathrm{CH}_{4}$ the least.
c. $\mathrm{CH}_{4}$ provides the most energy per gram and $\mathrm{C}_{2} \mathrm{H}_{2}$ the least.
d. $\mathrm{CH}_{4}$ provides the most energy per gram and $\mathrm{CH}_{3} \mathrm{OH}$ the least.

Hunza Gilgit

Numerade Educator

Problem 93

Calculate $\Delta \mathrm{H}_{\mathrm{f}}^{\circ}$ for chloride ion from the following data:
$1 / 2 \mathrm{H}_{2}(\mathrm{~g})+\mathrm{L} / 2 \mathrm{Cl}_{2}(\mathrm{~g}) \rightarrow \mathrm{HCl}(\mathrm{g})$
$\Delta \mathrm{H}_{\mathrm{f}}^{\circ}=-92.4 \mathrm{~kJ}$
$\mathrm{HCl}(\mathrm{g})+\mathrm{nH}_{2} \mathrm{O}(\mathrm{l}) \rightarrow \mathrm{H}^{+}(\mathrm{aq})+\mathrm{Cl}^{-}(\mathrm{aq})$
$\Delta \mathrm{H}_{298}=-74.8 \mathrm{~kJ}$
$\Delta \mathrm{H}_{\mathrm{f}}^{\mathrm{o}}\left[\mathrm{H}^{+}\right]=0.0 \mathrm{~kJ}$
a. $-189 \mathrm{~kJ}$
b. $-167 \mathrm{~kJ}$
c. $+167 \mathrm{~kJ}$
d. $-191 \mathrm{~kJ}$

Hunza Gilgit

Numerade Educator

Problem 94

The signs of $\Delta \mathrm{G}, \Delta \mathrm{H}$ and $\Delta \mathrm{S}$ at $25^{\circ} \mathrm{C}$ are shown below for three reactions.
Reaction $\Delta \mathrm{G}$ $\Delta \mathrm{H} \quad \Delta \mathrm{S}$
I. $+\quad+$
II. $+$
III. - - -
Which reaction could go in the reverse direction at high temperature?
a. II only
b. III only
c. I and II
d. II and III

Hunza Gilgit

Numerade Educator

Problem 95

The heat liberated on complete combustion of $7.8$ g benzene is $327 \mathrm{~kJ}$. This heat was measured at constant volume and at $27^{\circ} \mathrm{C}$. Calculate the heat of combustion of benzene at constant pressure ( $\mathrm{R}$ $\left.=8.3 \mathrm{~J} \mathrm{~mol}^{-1} \mathrm{~K}^{-1}\right)$
a. $-3274 \mathrm{~kJ} \mathrm{~mol}^{-1}$
b. $-1637 \mathrm{~kJ} \mathrm{~mol}^{-1}$
c. $-3270 \mathrm{~kJ} \mathrm{~mol}^{-1}$
d. $-3637 \mathrm{~kJ} \mathrm{~mol}^{-1}$

Mahipal Kumawat

Mahipal Kumawat

Numerade Educator

Problem 96

A given masss of gas expands from the state $\times$ to the staste $Y$ by three paths 1,2 and 3 as shown $I$ in the figure. If $w 1$ and $w_{2}$ and $w_{3}$ respectively be the work done by the gas along three paths then:
a. $\mathrm{W}_{1}>\mathrm{W}_{2}>\mathrm{W}_{3}$
b. $\mathrm{w}_{2}<\mathrm{w}_{1}<\mathrm{w}_{2}$
c. $\mathrm{W}_{1}=\mathrm{w}_{2}=\mathrm{w}_{3}$
d. $\mathrm{w}_{1}<\mathrm{w}_{2}<\mathrm{W}_{3}$

Hunza Gilgit

Numerade Educator

Problem 97

Calculate $\Delta \mathrm{G}^{\circ}$ for the reaction below and tell whether it is spontaneous or non-spontaneous under standard conditions at $25^{\circ} \mathrm{C}$.
$2 \mathrm{~S}(\mathrm{~s})+3 \mathrm{O}_{2}(\mathrm{~g})+2 \mathrm{H}_{2} \mathrm{O}(\mathrm{l}) \rightarrow 2 \mathrm{H}_{2} \mathrm{SO}_{4}(l)$
$\Delta \mathrm{H}^{\circ}=-1056 \mathrm{~kJ} / \mathrm{mol}$
$\Delta \mathrm{S}^{0}=-505 \mathrm{~J} / \mathrm{mol}$
a. $\Delta \mathrm{G}^{\circ}=-906 \mathrm{~kJ}$ and the process is spontaneous
b. $\Delta \mathrm{G}^{0}=-1206$ and the process is spontaneous
c. $\Delta \mathrm{G}^{\circ}=-906 \mathrm{~kJ}$ and the process is non-spontaneous
d. $\Delta \mathrm{G}^{0}=-1206 \mathrm{~kJ}$ and the process is non-spontaneous

Hunza Gilgit

Numerade Educator

Problem 98

Generally, alkali metals form their oxides by an average increment of $6 \mathrm{~kJ} \mathrm{~mol}^{-1} \mathrm{~K}^{-1}$ in their entropies. If at $25^{\circ} \mathrm{C}, \Delta \mathrm{G}_{\mathrm{f}}^{\mathrm{o}}$ of $\mathrm{Al}_{2} \mathrm{O}_{3}(\mathrm{~s})=-1582 \mathrm{~kJ} \mathrm{~mol}^{-1}$;
$\Delta \mathrm{H}_{i}^{\circ}$ of $\mathrm{Li}_{2} \mathrm{O}(\mathrm{s})=1244 \mathrm{~kJ}$ and $\Delta \mathrm{H}_{\mathrm{f}}^{\circ}$ of $\mathrm{Na}_{2} \mathrm{O}(\mathrm{s})=$
$1411 \mathrm{~kJ}$. The aluminium oxide can be reduced to Al metal by
a. Lithium
b. Sodium
c. Both (a) and (b)
d. None of these

Hunza Gilgit

Numerade Educator

Problem 99

For the reaction,
$$
\mathrm{A}(\mathrm{g})+2 \mathrm{~B}(\mathrm{~g}) \rightarrow 2 \mathrm{C}(\mathrm{g})+3 \mathrm{D}(\mathrm{g})
$$
The value of $\Delta \mathrm{H}$ at $27^{\circ} \mathrm{C}$ is $19.0 \mathrm{kcal}$. The value of $\Delta \mathrm{E}$ for the reaction would be
(given $\left.\mathrm{R}=2.0 \mathrm{cal} \mathrm{K}^{-1} \mathrm{~mol}^{-1}\right)$
a. $20.8 \mathrm{kcal}$
b. $19.8 \mathrm{kcal}$
c. $18.8 \mathrm{kcal}$
d. $17.8 \mathrm{kcal}$

Mahipal Kumawat

Mahipal Kumawat

Numerade Educator

Problem 100

Determine $\Delta \mathrm{H}$ and $\Delta \mathrm{E}$ for reversible isothermal evaporation of $90 \mathrm{~g}$ of water at $100^{\circ} \mathrm{C}$. Assume that water vapour behaves as an ideal gas and heat of evaporation of water is 540 cal $\mathrm{g}^{-1}(\mathrm{R}=$ $\left.2.0 \mathrm{cal} \mathrm{mol}^{-1} \mathrm{~K}^{-1}\right)$
a. 48600 cal, 44870 cal
b. 43670 cal, 47700 cal
c. 47700 cal, 43670 cal
d. 44870 cal, 48670 cal

Hunza Gilgit

Numerade Educator

Problem 101

If work done by a gas is $144.5 \mathrm{~J}$ when heat given to the gas in isobaric process is $506 \mathrm{~J}$. then the gas is
a. $\mathrm{SO}_{2}$
b. $\mathrm{NH}_{3}$
c. $\mathrm{He}$
d. $\mathrm{O}_{2}$

Hunza Gilgit

Numerade Educator

Problem 102

A process is carried out at constant pressure. Given that $\Delta \mathrm{H}$ is negative and $\Delta \mathrm{E}$ is less than $\Delta \mathrm{H}$,
a. The system loses heat and contracts during the process
b. The system loses heat and expands during the process
c. The system absorbs heat and expands during the process
d. The system absorbs heat and contracts during the process

Hunza Gilgit

Numerade Educator

Problem 103

$\Delta \mathrm{G}^{\circ}$ for the reaction, $\mathrm{x}+\mathrm{y} \leftrightarrow \mathrm{z}$ is $-4.606 \mathrm{kcal}$. The
value of equilibrium constant of the reaction at $227^{\circ} \mathrm{C}$ is.
a. $0.01$
b. 100
c. 2
d. 10

Mahipal Kumawat

Mahipal Kumawat

Numerade Educator

Problem 105

Assume a heteronuclear diatomic molecule, AB, forms a one dimensional crystal by lining up along the X-axis. Also assume that each molecule can only have one of six possible orientations, corresponding to atom A facing in either the positive or negative direction along the $\mathrm{X}-\mathrm{Y}=$, or $\mathrm{Z}-$ axis. If the molecules are arranged randomly in the six directions, the molar entropy at absolute zero should be
a. zero
b. $\mathrm{R} \operatorname{In} 60$
c. $\mathrm{R}$ In 6
d. $\mathrm{R} \operatorname{In} 6^{6}$

Hunza Gilgit

Numerade Educator

Problem 106

P-V plot for two gases (assuming ideal) during adiabatic process are given in the fig. Plot $X$ and plot $Y$ should correspond respectively to:
a. $\mathrm{He}$ and $\mathrm{H}_{2}$
b. $\mathrm{H}_{2}$ and $\mathrm{He}$
c. $\mathrm{Cl}_{2}$ and $\mathrm{H}_{2}$
d. $\mathrm{H}_{2}$ and $\mathrm{Cl}_{2}$

Hunza Gilgit

Numerade Educator

Problem 106

The solubility of manganese (II) fluoride in water is $6.6 \mathrm{~g} / \mathrm{ml}$ at $40^{\circ} \mathrm{C}$ and $4.8 \mathrm{~g}$ /litre at $100^{\circ} \mathrm{C}$. Based on this data, what is the sign of $\Delta \mathrm{H}^{\circ}$ and $\Delta \mathrm{S}^{\circ}$ for the following process?
$\mathrm{MnF}_{2}(\mathrm{~s}) \Rightarrow \mathrm{Mn}^{2+}(\mathrm{aq})+2 \mathrm{~F}^{-}(\mathrm{aq})$
a. $\Delta \mathrm{H}^{\circ}$ is negative and $\Delta \mathrm{S}^{\circ}$ is positive
b. $\Delta \mathrm{H}^{\circ}$ is negative and $\Delta \mathrm{S}^{\circ}$ is negative
c. $\Delta \mathrm{H}^{\circ}$ is positive and $\Delta \mathrm{S}^{\circ}$ is positive
d. $\Delta \mathrm{H}^{\circ}$ is positive and $\Delta \mathrm{S}^{\circ}$ is negative

Hunza Gilgit

Numerade Educator

Problem 107

For the system represented by the equation
$\mathrm{CaCO}_{3}(\mathrm{~s})+42.5 \mathrm{Kcal} \rightarrow \mathrm{CaO}(\mathrm{s})+\mathrm{CO}_{2}(\mathrm{~g})$
a. the reaction is exoenergic
b. the size of $\Delta \mathrm{E}$ is negative
c. the net energy flow is from the system to the environment
d. the internal chemical energy of one mole $\mathrm{CaCO}_{3}$
(s) is less than that of $[$ one mole $\mathrm{CaO}(\mathrm{s})+$ one mole $\left.\mathrm{CO}_{2}(\mathrm{~g})\right]$

Hunza Gilgit

Numerade Educator

Problem 108

(I) $\mathrm{Q}_{\mathrm{X}} \rightarrow \mathrm{Y}=(-)$ ve
(II) $\Delta \mathrm{U}_{\mathrm{Y}} \rightarrow Z=(+)$ ve
(III) $\Delta \mathrm{U}_{\mathrm{z}} \rightarrow \mathrm{x}=(-)$ ve
(IV) $\mathrm{W}_{\mathrm{ZXY}}=(-)$ ve.
a. I, II, III
b. I, II, IV
c. I, III, IV
d. II, III, IV

Hunza Gilgit

Numerade Educator

Problem 109

Consider these two statements.
(i) The reversible work done by 2 moles of an ideal gas, isothermally at $300 \mathrm{k}$, as it expands from 10 atm to 1 atm. pressure is roughly $2.764 \mathrm{k}$. cal.
(ii) 2 moles of a gas expand against a constant pressure of $1 \mathrm{~atm}$, the change in the volume being $82.12 \mathrm{ml}$. The work done by the gas is roughly 3 cal.
a. (i) and (ii) are correct
b. (i) and (ii) are incorrect
c. (i) is incorrect, (ii) is correct
d. (i) is correct, (ii) is incorrect

Himanshu Kushwaha

Himanshu Kushwaha

Numerade Educator

Problem 110

The reversible adiabatic expansion of an ideal monatomic gas, the final volume is 10 times to the initial volume. The ratio
Final temperature is Initial temperature
a. $(1 / 10)^{0.666}$
b. $10^{1.666}$
c. $10^{0.666}$
d. $(1 / 10)^{1.666}$

Hunza Gilgit

Numerade Educator

Problem 111

$4.8 \mathrm{~g}$ of $\mathrm{C}$ (diamond) on complete combustion evolves $1584 \mathrm{~kJ}$ of heat. The standard heat of formation of gaseous carbon is $725 \mathrm{~kJ} / \mathrm{mol}$. The energy required for the process
(i) $\mathrm{C}$ (graphite) $\rightarrow \mathrm{C}$ (gas)
(ii) $\mathrm{C}$ (diamond) $\rightarrow \mathrm{C}$ (gas) are
a. 725,723
b. 725,727
c. 727,725
d. None of these

Hunza Gilgit

Numerade Educator

Problem 112

Bond dissociation enthalpy of $\mathrm{H}_{2}, \mathrm{Cl}_{2}$ and $\mathrm{HCl}$ are 434, 242 and $431 \mathrm{~kJ} \mathrm{~mol}^{-1}$ respectively. Enthalpy of formation of $\mathrm{HCl}$ is
a. $-93 \mathrm{~kJ} \mathrm{~mol}^{-1}$
b. $245 \mathrm{~kJ} \mathrm{~mol}^{-1}$
c. $93 \mathrm{~kJ} \mathrm{~mol}^{-1}$
d. $-245 \mathrm{~kJ} \mathrm{~mol}^{-1}$

Hunza Gilgit

Numerade Educator

Problem 113

Consider the reaction:
$\mathrm{N}_{2}(\mathrm{~g})+3 \mathrm{~F}_{2}(\mathrm{~g}) \rightarrow 2 \mathrm{NF}_{3}(\mathrm{~g})$
$\Delta \mathrm{H}^{\circ}=-249 \mathrm{~kJ}$ and $\Delta \mathrm{S}^{\circ}=-278 \mathrm{JK}^{-1}$ at $25^{\circ} \mathrm{C}$
Calculate $\Delta \mathrm{G}^{\circ}$ and state whether the equilibrium composition should favour reactants or products at standard conditions.
a. $\Delta \mathrm{G}^{\circ}=-166 \mathrm{~kJ} ;$ the equilibrium composition should favour reactants.
b. $\Delta \mathrm{G}^{\circ}=-166 \mathrm{~kJ} ;$ the equilibrium composition should favour products.
c. $\Delta \mathrm{G}^{\circ}=-322 \mathrm{~kJ}$; the equilibrium composition should favour products.
d. $\Delta G^{\circ}=-166 \mathrm{~kJ} ;$ the equilibrium composition should favour reactants.

Hunza Gilgit

Numerade Educator

Problem 114

Which provides the greatest increase in entropy?
a. $\mathrm{H}_{2} \mathrm{O}\left(\mathrm{l}, 0^{\circ} \mathrm{C}\right) \rightarrow \mathrm{H}_{2} \mathrm{O}\left(1,25^{\circ} \mathrm{C}\right)$
b. $\mathrm{H}_{2} \mathrm{O}\left(\mathrm{s}, 0^{\circ} \mathrm{C}\right) \rightarrow \mathrm{H}_{2} \mathrm{O}\left(\mathrm{l}, 0^{\circ} \mathrm{C}\right)$
c. $\mathrm{H}_{2} \mathrm{O}\left(\mathrm{l}, 100^{\circ} \mathrm{C}\right) \rightarrow \mathrm{H}_{2} \mathrm{O}\left(\mathrm{g}, 100^{\circ} \mathrm{C}\right)$
d. $\mathrm{H}_{2} \mathrm{O}\left(\mathrm{g}, 0.1^{\circ} \mathrm{C}\right) \rightarrow \mathrm{H}_{2} \mathrm{O}\left(\mathrm{s}, 0.1^{\circ} \mathrm{C}\right)$

Hunza Gilgit

Numerade Educator

Problem 115

Consider these two statements.
(I) The reversible work done by 2 moles of an ideal gas, isothermally at $300 \mathrm{k}$, as it expands from 10 atm to 1 atm. pressure is roughly $2.764 \mathrm{k}$. cal.
(II) 2 moles of a gas expand against a constant pressure of $1 \mathrm{~atm}$, the change in the volume being $82.12 \mathrm{ml}$. The work done by the gas is roughly 3 cal.
a. (i) and (ii) are correct
b. (i) and (ii) are incorrect
c. (i) is incorrect, (ii) is correct
d. (i) is correct, (ii) is incorrect

Hunza Gilgit

Numerade Educator

Problem 116

(Standard free energies of formation (in $\mathrm{kJ} / \mathrm{mol}$ ) at $298 \mathrm{~K}$ are $-237.2,-394.4$ and $-8.2$ for $\mathrm{H}_{2} \mathrm{O}$ (I), $\mathrm{CO}_{2}$
(g) are pentane $(\mathrm{g})$ respectively. The value of $\mathrm{E}_{\mathrm{ccll}^{\circ}}$ for the pentane-oxygen fuel cell is:
a. $1.0968 \mathrm{~V}$
b. $0.0698 \mathrm{~V}$
c. $1.968 \mathrm{~V}$
d. $2.0968 \mathrm{~V}$
Given that
$3 \mathrm{C}(\mathrm{s})+2 \mathrm{Fe}_{2} \mathrm{O}_{3}(\mathrm{~s}) \rightarrow 4 \mathrm{Fe}(\mathrm{s})+3 \mathrm{CO}_{2}(\mathrm{~g})$
$\Delta \mathrm{H}^{\circ}=-93657 \mathrm{kcal}$ at $25^{\circ} \mathrm{C}$
$\mathrm{C}(\mathrm{s})+\mathrm{O}_{2}(\mathrm{~g}) \rightarrow \mathrm{CO}_{2}(\mathrm{~g})$
$\Delta \mathrm{H}^{\circ}=-94050 \mathrm{kcal}$ at $25^{\circ} \mathrm{C}$
The value of $\Delta \mathrm{H}^{\circ}\left(\mathrm{Fe}_{2} \mathrm{O}_{3}\right)$ is
a. $-19.650 \mathrm{kcal}$
b. $-196.5 \mathrm{kcal}$
c. $93.657 \mathrm{kcal}$
d. $-286.4 \mathrm{kcal}$

Hunza Gilgit

Numerade Educator

Problem 117

The enthalpy of solution of $\mathrm{BaCl}_{2}$ (s) and $\mathrm{BaCl}_{2} \cdot 2 \mathrm{H}_{2} \mathrm{O}(\mathrm{s})$ are $-20.6$ and $8.8 \mathrm{~kJ} \mathrm{~mol}^{-1}$ respec-
tively. The enthalpy change for the hydration of $\mathrm{BaCl}_{2}(\mathrm{~s})$ is
a. $29.8 \mathrm{~kJ}$
b. $-11.8 \mathrm{~kJ}$
c. $-20.6 \mathrm{~kJ}$
d. $-29.4 \mathrm{~kJ}$.

Hunza Gilgit

Numerade Educator

Problem 118

The heat of formation of $\mathrm{CO}_{2}$ is $-409 \mathrm{~kJ} / \mathrm{mol}$. The energy required for the process
$3 \mathrm{CO}_{2}(\mathrm{~g}) \rightarrow 3 \mathrm{C}(\mathrm{g})+2 \mathrm{O}_{3}(\mathrm{~g})$ is
a. Is equal to $1227 \mathrm{~kJ}$
b. Less than $1227 \mathrm{~kJ}$
c. More than $1227 \mathrm{~kJ}$
d. Cannot be predicted

Hunza Gilgit

Numerade Educator

Problem 119

Calculate $\mathrm{Q}$ and $\mathrm{W}$ for the isothermal reversible expansion of one mole of an ideal gas from an initial pressure of $1.0$ bar to a final pressure of $0.1$ bar at a constant temperature of $273 \mathrm{~K}$.
a. $5.22 \mathrm{~kJ},-5.22 \mathrm{~kJ}$
b. $-27.3 \mathrm{~kJ}, 27.3 \mathrm{~kJ}$
c. $27.3 \mathrm{~kJ},-27.3 \mathrm{~kJ}$
d. $-5.22 \mathrm{~kJ}, 5.22 \mathrm{~kJ}$

Mahipal Kumawat

Mahipal Kumawat

Numerade Educator

Problem 120

Calculate the heat of combustion of methane at constant volume. The thermal capacity of the calorimeter system is $177 \mathrm{~kJ} \mathrm{~K}^{-1}\left(\mathrm{R}=8.314 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}\right)$
a. $-695 \mathrm{~kJ} \mathrm{~mol}^{-1}$
b. $-1703 \mathrm{~kJ} \mathrm{~mol}^{-1}$
c. $-890 \mathrm{~kJ} \mathrm{~mol}^{-1}$
d. $-885 \mathrm{~kJ} \mathrm{~mol}^{-1}$

Hunza Gilgit

Numerade Educator

Problem 121

If a copper block of mass $\mathrm{m}$ at temperature 'T1' is kept in the open atmosphere at temperature 'T2' and $\mathrm{T} 2>\mathrm{T} 1$. The variation of entropy of the copper block with time can be best illustrated by which of these graph.

Himanshu Kushwaha

Himanshu Kushwaha

Numerade Educator

Problem 122

The lattice energy of $\mathrm{NaCl}$ is $780 \mathrm{~kJ} \mathrm{~mol}^{-1}$ The enthalpies of hydration of $\mathrm{Na}^{+}(\mathrm{g})$ and $\mathrm{Cl}^{-}(\mathrm{g})$ ions are $-406$ $\mathrm{kJ} \mathrm{mol}^{-1}$ and $-364 \mathrm{~kJ} \mathrm{~mol}^{-1}$. The enthalpy of solution of $\mathrm{NaCl}(\mathrm{s})$ is
a. $10 \mathrm{~kJ} \mathrm{~mol}^{-1}$
b. $-10 \mathrm{~kJ} \mathrm{~mol}^{-1}$
c. $736 \mathrm{~kJ} \mathrm{~mol}^{-1}$
d. $100 \mathrm{~kJ} \mathrm{~mol}^{-1}$

Hunza Gilgit

Numerade Educator

Problem 124

The enthalpy (heat) of formation of water is $286 \mathrm{~kJ}$ $\mathrm{mole}^{-1}$. From this it can be concluded that
a. the enthalpy change when $1 \mathrm{~g}$ of hydrogen is burnt in oxygen is $-286 \mathrm{~kJ}$
b. there is a decrease in the enthalpy of the system when water is formed
c. the mean bond dissociation energy of $\mathrm{O}-\mathrm{H}$ is $143 \mathrm{~kJ} \mathrm{~mol}^{-1}$
d. the enthalpy change for the reaction $\mathrm{H}^{+}(\mathrm{aq})+\mathrm{OH}^{-}(\mathrm{aq}) \rightarrow \mathrm{H}_{2} \mathrm{O}(l)$ is $-286 \mathrm{~kJ} \mathrm{~mol}^{-1}$

Hunza Gilgit

Numerade Educator

Problem 125

Which of these correctly represents the entropy (s) of an isolated system during a process?

Himanshu Kushwaha

Himanshu Kushwaha

Numerade Educator

Problem 126

Which of the following statement is/are correct?
a. From the following reaction
$$
\mathrm{CO}(\mathrm{g})+\mathrm{O}_{2}(\mathrm{~g}) \rightarrow \mathrm{CO}_{2}(\mathrm{~g}), \Delta \mathrm{H}=\mathrm{q}_{1}
$$
Heat of formation of $\mathrm{CO}_{2}(\mathrm{~g})$ is $\mathrm{q}_{1}$
b. From the following reaction
$$
\mathrm{C} \text { (graphite) }+1 / 2 \mathrm{O}_{2}(\mathrm{~g}) \rightarrow \mathrm{CO}(\mathrm{g}), \Delta \mathrm{H}=\mathrm{q}_{2}
$$
Heat of combustion of carbon is $\mathrm{q}_{2}$.
c. From the above reaction, heat of combustion of $\mathrm{CO}(\mathrm{g})$ is $\mathrm{q}_{1}$ and that of carbon is $\mathrm{q}_{1}+\mathrm{q}_{2}$.
d. From the above reaction, heat of formation of $\mathrm{CO}_{2}$ is $\mathrm{q}_{1}+\mathrm{q}_{2}$

Hunza Gilgit

Numerade Educator

Problem 127

Which of the following statements is/are true?
a. A highly spontaneous process need not occur rapidly
b. A non spontaneous process cannot be caused to occur.
c. The reverse of a spontaneous reaction is always non spontaneous.
d. A spontaneous process always moves towards equilibrium.

Hunza Gilgit

Numerade Educator

Problem 128

$\mathrm{C}_{\mathrm{p}}-\mathrm{C}_{\mathrm{V}}=\mathrm{R}$. This $\mathrm{R}$ is not equal to:
a. Change in rotational energy
b. Change in $\mathrm{KE}$
c. Change in $\mathrm{PE}$
d. Work done which system can do on expanding the gas per mol per degree increase in temperature.

Hunza Gilgit

Numerade Educator

Problem 129

For which of the following reaction is the standard entropy of reaction $\Delta \mathrm{S}^{\circ}$ positive?
a. $\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}(\mathrm{l})+3 \mathrm{O}_{2}(\mathrm{~g}) \rightarrow 2 \mathrm{CO}_{2}(\mathrm{~g})+3 \mathrm{H}_{2} \mathrm{O}(l)$
b. $2 \mathrm{H}_{2} \mathrm{O}(\mathrm{g}) \rightarrow 2 \mathrm{H}_{2}(\mathrm{~g})+\mathrm{O}_{2}(\mathrm{~g})$
c. $\mathrm{CO}(\mathrm{g})+2 \mathrm{H}_{2}(\mathrm{~g}) \rightarrow \mathrm{CH}_{3} \mathrm{OH}(\mathrm{g})$
d. $\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}(\mathrm{g})+3 \mathrm{O}_{2}(\mathrm{~g}) \rightarrow 2 \mathrm{CO}_{2}(\mathrm{~g})+3 \mathrm{H}_{2} \mathrm{O}(\mathrm{g})$

Hunza Gilgit

Numerade Educator

Problem 130

The enthalpy change for a reaction depend upon the
a. physical state of reactants and products
b. use of different reactants for the same product
c. nature of intermediate reaction steps
d. difference in initial or final temperatures of involved substances

Rajesh Singh

Numerade Educator

Problem 131

Which of the following always increase with increase in temperature?
a. pressure of the gas at constant volume
b. solubility of gas
c. entropy
d. rate of reaction

Hunza Gilgit

Numerade Educator

Problem 132

Which of the following is/are spontaneous process?
a. $2 \mathrm{NH}_{3}(\mathrm{~g}) \rightarrow \mathrm{N}_{2}(\mathrm{~g})+3 \mathrm{H}_{2}(\mathrm{~g})$ if $\mathrm{p}_{\mathrm{NH}_{3}}=1 \mathrm{~atm}$,
$\mathrm{p}_{\mathrm{H}_{2}}=\mathrm{P}_{\mathrm{N}_{2}}=0$ and $\mathrm{Kp}=2 \times 10^{-6}$
b. $\mathrm{N}_{2}(\mathrm{~g})+3 \mathrm{H}_{2}(\mathrm{~g}) \rightarrow 2 \mathrm{NH}_{3}(\mathrm{~g})$ if $\mathrm{pH}_{2}=\mathrm{PN}_{2}=1$
atm, $\mathrm{pNH}_{3}=0$ and $\mathrm{Kp}=4 \times 10^{5}$
c. the expansion of gas into a vacuum
d. dissolving more solute in a saturated solution

Hunza Gilgit

Numerade Educator

Problem 133

Internal energy and entropy are state functions
a. internal energy (U) is a state function and $\Delta \mathrm{U}$ is independent of path.
b. In a cyclic process: $\Delta \mathrm{S}=0$ but $\Delta \mathrm{U} \neq 0$
c. $\mathrm{Cv}$ values of $\mathrm{H}_{2}$ and He are equal at all temperatures
d. $\mathrm{q}$ and $\mathrm{w}$ are path dependent

Hunza Gilgit

Numerade Educator

Problem 134

For which of the following processes will the entropy decrease?
a. Reaction of magnesium with oxygen to form magnesium oxide.
b. Reaction of nitrogen and hydrogen to form ammonia.
c. Sublimation of dry ice.
d. Condensation of steam.

Hunza Gilgit

Numerade Educator

Problem 135

Which of the following statements must be true for the entropy of a pure solid to be zero?
a. Temperature must be $0 \mathrm{~K}$.
b. The solid must be perfectly ordered
c. The solid must be an element.
d. The solid must be crystalline, not amorphous

Hunza Gilgit

Numerade Educator

Problem 136

For an ideal gas undergoing isothermal and reversible process
a. $\Delta \mathrm{U}$ and $\Delta \mathrm{H}$ both are zero
b. $\Delta \mathrm{U}=0$ but $\Delta \mathrm{H} \neq 0$
c. $\Delta \mathrm{S}$ is $+$ ve during expansion and -ve during compression
d. $\Delta \mathrm{S}=0$ and $\Delta \mathrm{U}=0$

Hunza Gilgit

Numerade Educator

Problem 137

In certain chemical process both $\Delta \mathrm{H}$ and $\Delta \mathrm{S}$ have values greater than zero. Under what conditions, the reaction would not be spontaneous?
a. $\Delta \mathrm{H}>\mathrm{T} \Delta \mathrm{S}$
b. $\Delta \mathrm{H}<\mathrm{T} \Delta \mathrm{S}$
c. $\Delta \mathrm{G}>0$
d. $\Delta \mathrm{G}<0$

Ivan Kochetkov

Numerade Educator

Problem 138

Which statement is/are not true about the standard states of $\mathrm{F}_{2}$ (g) and $\mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6}$ (aq)?
a. The standard state for $\mathrm{F}_{2}(\mathrm{~g})$ is the pure gas at 1 atm and for $\mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6}(\mathrm{aq})$ is the solution at a concentration of $1 \mathrm{~mol} / \mathrm{L}$.
b. The standard state for $\mathrm{F}_{2}(\mathrm{~g})$ is the pure gas at $1 \mathrm{~mol} / \mathrm{L}$ and for $\mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6}$ (aq) is the solution at
a concentration of $1 \mathrm{~mol} / \mathrm{L}$.
c. The standard state for $\mathrm{F}_{2}(\mathrm{~g})$ is the pure gas at $1 \mathrm{~atm}$ and for $\mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6}$ (aq) is the pure solid at $1 \mathrm{~atm}$.
d. The standard state for $\mathrm{F}_{2}(\mathrm{~g})$ is the pure gas at 1 $\mathrm{mol} / \mathrm{L}$ and for $\mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6}(\mathrm{aq})$ is the pure solid at
atm.

Himanshu Kushwaha

Himanshu Kushwaha

Numerade Educator

Problem 139

The heat evolved during the combustion of $46 \mathrm{gm}$ of ethanol in a bomb calorimeter wad determined to be $670.5 \mathrm{kcal} / \mathrm{mol}$ at $25^{\circ} \mathrm{C}$. The value of $\Delta \mathrm{U}$ of the reaction at the same temperature is
a. $-335.25 \mathrm{Kcal}$
b. $-660.3 \mathrm{Kcal}$
c. $-670.5 \mathrm{Kcal}$
d. $-2802.6 \mathrm{~kJ}$

Hunza Gilgit

Numerade Educator

Problem 140

Which of the following process/es proceed towards more disordered state?
a. sublimation of dry ice
b. crystallization of salt from solution
c. dissolution of sugar in water
d. stretching of the rubber

Hunza Gilgit

Numerade Educator

Problem 141

Identify the incorrect statement/s regarding entropy.
a. at absolute zero temperature, entropy of perfectly crystalline substance is taken to zero
b. at absolute zero temperature, the entropy of perfectly crystalline substance is positive
c. at $0^{\circ} \mathrm{C}$ the entropy of perfectly crystalline substance is positive
d. at absolute zero temperature, the entropy of all crystalline substances is taken to be zero

Hunza Gilgit

Numerade Educator

Problem 142

$\mathrm{xy}, \mathrm{x}_{2}$ and $\mathrm{y}_{2}$ are diatomic molecules if $\Delta \mathrm{H}_{\mathrm{x}-\mathrm{x}}, \Delta \mathrm{H}_{y-y}$
and $\Delta \mathrm{Hxy}$ are in the ratio of $2: 1: 2$ and enthalpy of formation of $x$-y form $x_{2}$ and $y_{2}$ is $-100 \mathrm{~kJ} /$ mol. The value of $\Delta \mathrm{Hx}-\mathrm{x}$ is
a. $47.85 \mathrm{Kcal} / \mathrm{mol}$
b. $23.92 \mathrm{Kcal} / \mathrm{mol}$
c. $100 \mathrm{~kJ} / \mathrm{mol}$
d. $200 \mathrm{Kcal} / \mathrm{mol}$

Hunza Gilgit

Numerade Educator

Problem 143

Which of the following statement is/are true?
a. work is a state function
b. temperature is a state function
c. change in the state is completely defined when the initial and final state are specified
d. all of them

Hunza Gilgit

Numerade Educator

Problem 144

Which of the following is/are true?
a. A spontaneous process is one that can proceed on its own.
b. The reverse of a non-spontaneous process is always spontaneous.
c. A spontaneous process need not occur immediately.
d. A spontaneous process must be exothermic and must have an increase in entropy.

Hunza Gilgit

Numerade Educator

Problem 145

Which of the following expression is correct for an adiabatic process?
a. $\left(\mathrm{T}_{2} / \mathrm{T}_{1}\right)=\left(\mathrm{V}_{1} / \mathrm{V}_{2}\right)^{\mathrm{y}-1}$
b. $\mathrm{P}_{2} / \mathrm{P}_{1}=\left(\mathrm{T}_{1} / \mathrm{T}_{2}\right)^{\gamma-1 / \mathrm{r}}$
c. $\mathrm{P}_{2} \mathrm{~V}_{2}^{\gamma}=\mathrm{P}_{1} \mathrm{~V}_{1}^{\gamma}$
d. $\mathrm{P}_{1} \mathrm{~V}_{1}^{-1}=\mathrm{P}_{2} \mathrm{~V}_{2}{ }^{\gamma-1}$

Hunza Gilgit

Numerade Educator

Problem 146

For which change $\Delta \mathrm{H}=\Delta \mathrm{E}$
a. $\mathrm{H}_{2}+\mathrm{I}_{2} \leftrightarrow 2 \mathrm{HI}$
b. $\mathrm{HCl}+\mathrm{NaOH} \rightarrow \mathrm{NaCl}+\mathrm{H}_{2} \mathrm{O}$
c. $\mathrm{C}(\mathrm{s})+\mathrm{O}_{2}(\mathrm{~g}) \leftrightarrow \mathrm{CO}_{2}(\mathrm{~g})$
d. $\mathrm{N}_{2}+3 \mathrm{H}_{2} \rightarrow 2 \mathrm{NH}_{3}$

Hunza Gilgit

Numerade Educator

Problem 147

Which statement is/ are not true about the formation of $\mathrm{CaCO}_{3}$ (s) from $\mathrm{CaO}(\mathrm{s})$ and $\mathrm{CO}_{2}$ (g) at $1.00 \mathrm{~atm} ?$
$\mathrm{CaO}(\mathrm{s})+\mathrm{CO}_{2}(\mathrm{~g}) \rightarrow \mathrm{CaCO}_{3}(\mathrm{~s})$
$\Delta \mathrm{H}^{\circ}=-178.7 \mathrm{~kJ}$ and $\Delta \mathrm{S}^{\circ}=-150.4 \mathrm{JK}^{-1}$
a. The reaction is spontaneous at low temperature.
b. The reaction is spontaneous at all temperatures.
c. The reaction is not spontaneous at any temperature
d. The reaction is spontaneous at high temperatures.

Hunza Gilgit

Numerade Educator

Problem 148

The correct statement/s among the following is/are
a. mass plus energy of the universe remains always constant while entropy of the universe remains increasing continuously
b. an exothermic reaction with $\Delta \mathrm{S}$ being positive, will be spontaneous only at high temperature
c. in a reversible process, the system always in equilibrium with surroundings
d. in any cyclic process $\Delta \mathrm{X}=0$ where $\mathrm{X}$ is a state fuction.

Hunza Gilgit

Numerade Educator

Problem 149

Which of the following reaction is exothermic?
a. $\mathrm{C}$ (diamond) $\rightarrow \mathrm{C}$ (graphite)
b. $\mathrm{C}_{2} \mathrm{H}_{6} \rightarrow \mathrm{C}_{2} \mathrm{H}_{4}+\mathrm{H}_{2}$
c. $\mathrm{C}_{2} \mathrm{H}_{6}+7 / 2 \mathrm{O}_{2} \rightarrow 2 \mathrm{CO}_{2}+3 \mathrm{H}_{2} \mathrm{O}$ (I)
d. $2 \mathrm{NaOH}(\mathrm{aq})+\mathrm{H}_{2} \mathrm{SO}_{4}(\mathrm{aq}) \rightarrow$
$$
\mathrm{Na}_{2} \mathrm{SO}_{4}(\mathrm{aq})+2 \mathrm{H}_{2} \mathrm{O} \text { (l) }
$$

Hunza Gilgit

Numerade Educator

Problem 150

For which reaction change of entropy will be negative?
a. $\mathrm{H}_{2(\mathrm{~g})}+\mathrm{I}_{2(\mathrm{~g})}=2 \mathrm{HI}_{(\mathrm{g})}$
b. $\mathrm{MgO}_{(\mathrm{s})}+\mathrm{H}_{2(\mathrm{~g})}=\mathrm{Mg}_{(\mathrm{g})}+\mathrm{H}_{2} \mathrm{O}_{(1)}$
c. $\mathrm{NH}_{4} \mathrm{NO}_{3(s)}=\mathrm{N}_{2} \mathrm{O}_{(\mathrm{g})}+2 \mathrm{H}_{2} \mathrm{O}_{(\mathrm{gi}}$
d. $\mathrm{HCl}_{(\mathrm{g})}+\mathrm{NH}_{3(\mathrm{~g})}=\mathrm{NH}_{4} \mathrm{Cl}_{(s)}$

Hunza Gilgit

Numerade Educator

Problem 151

The correct statement amongst the following is/are
a. at equilibrium $\Delta \mathrm{H}_{\mathrm{s}, \mathrm{p}}=0$
b. the condition of equilibrium at constant $\mathrm{P}$ and $\mathrm{T}$ is that $\mathrm{G}$ must be minimum
c. at equilibrium $\Delta \mathrm{G}_{\mathrm{p}, \mathrm{T}}=0$
d. $\Delta$ G o calculated using the equation; $\Delta \mathrm{G}^{\mathrm{o}}=-\mathrm{RT}$ In $\mathrm{Kp}$, is the free energy change of the reaction when each of the species (reactants and products) is in the standard state of unit activity that is, roughly unit concentration.

Hunza Gilgit

Numerade Educator

Problem 152

Correct statement among the following is/are
a. mass plus energy of the universe remains always constant while entropy of the universe remains increasing continuously
b. an exothermic reaction with $\Delta \mathrm{S}$ being positive, will be spontaneous only at high temperature
c. in a reversible process the system always in equilibrium with surroundings
d. in any cyclic process $\Delta \mathrm{X}=0$ where Xs a state fuction.

Hunza Gilgit

Numerade Educator

Problem 153

The enthalpy change for a reaction depends upon:
a. The differences in initial or final temperatures of involved substances
b. The nature of intermediate reaction steps
c. Use of different reactants for the same product
d. The physical states of reactants and products

Hunza Gilgit

Numerade Educator

Problem 154

Which of the following is/are correct?
a. Numerical value of $\Delta \mathrm{H}$ is less than that of $\Delta \mathrm{E}$ for the reaction $\mathrm{C}(\mathrm{s})+1 / 2 \mathrm{O}_{2}(\mathrm{~g}) \rightleftharpoons \mathrm{CO}(\mathrm{g})$
b. In an exothermic reaction, the enthalpy of products is less than that of the reactants
c. $\Delta \mathrm{H}$ (fusion $)=\Delta \mathrm{H}(\mathrm{sub})-\Delta \mathrm{H}$ (vap)
d. A reaction for which $\Delta \mathrm{H}^{\circ}<0$ and $\Delta \mathrm{S}^{\circ}>0$ is possible at all temperatures.

Hunza Gilgit

Numerade Educator

Problem 155

Among the following, the state function(s) is/are
a. Internal energy
b. Irreversible expansion work
c. Reversible expansion work
d. Molar enthalpy

Prem Bijarniya

Numerade Educator

Problem 156

The process $\mathrm{X} \rightarrow \mathrm{Y}$ is isochoric. The volume of the gas numerically in this process is
a. $3 \mathrm{R}$
b. $3 \mathrm{R}$
c. $5 / 2 \mathrm{R}$
d. $2 \mathrm{R}$

Hunza Gilgit

Numerade Educator

Problem 157

The same cyclic process in the PV - diagram is

Hunza Gilgit

Numerade Educator

Problem 158

During the process $\mathrm{X} \rightarrow \mathrm{Y}$, The internal energy of the gas
a. Depends on volume
b. Decreases
c. Increases
d. Does not change

Hunza Gilgit

Numerade Educator

Problem 159

If the value of equilibrium constant for the reaction given below is $4.4 \times 10^{-4}$ at $298 \mathrm{~K}$.
$\mathrm{CH}_{3} \mathrm{NH}_{2}(\mathrm{aq})+\mathrm{H}_{2} \mathrm{O}(l)=\mathrm{CH}_{3} \mathrm{NH}_{3}^{+}(\mathrm{aq})+\mathrm{OH}^{-}(\mathrm{aq})$
Find $\Delta \mathrm{G}^{0}$ for this reaction.
a. $-38.28 \mathrm{~kJ}$
b. $-19.14 \mathrm{~kJ}$
c. $-9.57 \mathrm{~kJ}$
d. Zero

Hunza Gilgit

Numerade Educator

Problem 160

Find the value of $\Delta \mathrm{G}$ when $\left[\mathrm{H}^{+}\right]=3.0 \times 10^{-10}$ $\mathrm{M},\left[\mathrm{CH}_{3} \mathrm{NH}_{3}^{+}\right]=8.0 \times 10^{-3} \mathrm{M}$, and $\left[\mathrm{CH}_{3} \mathrm{NH}_{2}\right]$
$=0.070 \mathrm{M}$
a. $+11.8$
b. $-5.9$
c. $-10.8$
d. $-11.8$

Hunza Gilgit

Numerade Educator

Problem 161

A particular reaction given below can be spontaneous if
$2 \mathrm{POCl}_{3}(\mathrm{~g}) \rightarrow 2 \mathrm{PCL}_{3}(\mathrm{~g})+\mathrm{O}_{2}(\mathrm{~g})$
$\Delta \mathrm{H}^{\circ}=572 \mathrm{~kJ} ; \Delta \mathrm{S}^{\circ}=179 \mathrm{~J} / \mathrm{K}$
a. $\mathrm{T}>1200 \mathrm{~K}$
b. $\mathrm{T}>1600 \mathrm{~K}$
c. $\mathrm{T}>2400 \mathrm{~K}$
d. $T>3200 \mathrm{~K}$

Hunza Gilgit

Numerade Educator

Problem 162

The value of $\log _{10} \mathrm{k}_{\mathrm{eq}}$ (equilibrium constant) can be given as
a. $\frac{\Delta \mathrm{G}^{\circ}}{\mathrm{RT}}$
b. $\frac{\mathrm{T} \Delta \mathrm{S}^{\circ}-\Delta \mathrm{H}^{\circ}}{2.303 \mathrm{RT}}$
c. $\frac{\Delta \mathrm{H}^{\circ}-\mathrm{T} \Delta \mathrm{S}^{\circ}}{2.303 \mathrm{RT}}$
d. $\frac{2.303 \mathrm{RT}}{\mathrm{T} \Delta \mathrm{S}^{\mathrm{o}}-\Delta \mathrm{H}^{\circ}}$

Hunza Gilgit

Numerade Educator

Problem 163

Which diagram represents the large value of equilibrium constant for the reversible reaction?

Himanshu Kushwaha

Himanshu Kushwaha

Numerade Educator

Problem 164

The temperature dependence of the equilibrium constant can be given by the equation
a. $\ln \mathrm{K}=\frac{\Delta \mathrm{H}^{\circ}}{\mathrm{R}}\left(\frac{1}{\mathrm{~T}}\right)+\frac{\Delta \mathrm{S}^{\circ}}{\mathrm{R}}$
b. $\ln \mathrm{K}=-\frac{\Delta \mathrm{H}^{\circ}}{\mathrm{R}}\left(\frac{1}{\mathrm{~T}}\right)+\frac{\Delta \mathrm{S}^{\circ}}{\mathrm{R}}$
c. $\ln \mathrm{K}=\frac{\Delta \mathrm{G}^{\circ}}{\mathrm{R}}\left(\frac{1}{\mathrm{~T}}\right)+\frac{\Delta \mathrm{S}^{\circ}}{\mathrm{R}}$
d. $\ln \mathrm{K}=-\frac{\Delta \mathrm{G}^{\circ}}{\mathrm{R}}(\mathrm{T})+\frac{\Delta \mathrm{S}^{\circ}}{\mathrm{R}}$

Hunza Gilgit

Numerade Educator

Problem 165

Process, $\mathrm{X} \rightarrow \mathrm{Y}$ represents
a. Isobaric
b. isochoric
c. isothermal
d. adiabatic

Hunza Gilgit

Numerade Educator

Problem 166

The pressure at $\mathrm{Z}$ is
a. $3.518 \mathrm{~atm}$
b. $1.368 \mathrm{~atm}$
c. $0.0821$ atm
d. $0.821 \mathrm{~atm}$

Hunza Gilgit

Numerade Educator

Problem 167

The process which occurs in going from, $\mathrm{Y} \rightarrow \mathrm{Z}$ is
a. isothermal
b. adiabatic
c. isochoric
d. isobaric

Hunza Gilgit

Numerade Educator

Problem 168

The element gallium, Ga, freezes at $2.8^{\circ} \mathrm{C}$, and its enthalpy of fusion is $\Delta \mathrm{H}_{\mathrm{fis}}=5.59 \mathrm{~kJ} / \mathrm{mol}$. Calculate the value of $\Delta \mathrm{S}$ for the freezing of $90.0 \mathrm{~g}$ of $\mathrm{Ga}(l)$ at $29.8^{\circ} \mathrm{C}$.
a. $47.6 \mathrm{~J} / \mathrm{K}$
b. $23.8 \mathrm{~J} / \mathrm{K}$
c. $4.76 \mathrm{~J} / \mathrm{K}$
d. $32.86 \mathrm{~J} / \mathrm{K}$

Hunza Gilgit

Numerade Educator

Problem 169

Write the correct sequence of entropy change when a solid melt, a gas liquefies, liquid vapourizes and a solid dissolves in water.
a. Increases, increases, increases, increases respectively
b. Increases, decreases, increases, decreases respectively
c. Increases, decreases, increases, increases respectively
d. Decreases, increases, decreases, increases respectively

Hunza Gilgit

Numerade Educator

Problem 170

Find the entropy change when $0.5 \mathrm{M}$ of an ideal gas expands at a constant temperature from an initial volume of $10 \mathrm{~L}$ to a final volume of $75 \mathrm{~L}$.
a. $8.376 \mathrm{~J} / \mathrm{K}$
b. $4.188 \mathrm{~J} / \mathrm{K}$
c. $16.752 \mathrm{~J} / \mathrm{K}$
d. $7.367 \mathrm{~J} / \mathrm{K}$

Hunza Gilgit

Numerade Educator

Problem 171

(A): The enthalpy of formation of $\mathrm{H}_{2} \mathrm{O}(l)$ is greater than that of $\mathrm{H}_{2} \mathrm{O}(\mathrm{g})$
$(\mathbf{R})$ : Enthalpy change is $-$ ve for the condensation reaction, $\mathrm{H}_{2} \mathrm{O}(\mathrm{g}) \rightarrow \mathrm{H}_{2} \mathrm{O}$ (l)

Hunza Gilgit

Numerade Educator

Problem 172

$($ A $): \mathrm{Cp}-\mathrm{Cv}=\mathrm{R}$ for ideal gas
$(\mathbf{R}):(\mathrm{dU} / \mathrm{dV})_{\mathrm{T}}=0$ for ideal gas

Hunza Gilgit

Numerade Educator

Problem 173

(A): All combustion reactions are exothermic.
(R): Products are more stable than reactants in exothermic process.

Hunza Gilgit

Numerade Educator

Problem 174

(A): Chlorine when tried to be solidified does not have zero entropy when at absolute zero.
(R): Chlorine contains a mixture of isotopes and is difficult to solidify.

Hunza Gilgit

Numerade Educator

Problem 175

(A): Heat of neutralization of HF is more than that of $\mathrm{HCl}$ by $\mathrm{NaOH}$.
$(\mathbf{R}): \mathrm{HCl}$ is stronger acid than HF.

Hunza Gilgit

Numerade Educator

Problem 176

(A): The thermodynamic function which determines the spontaneity of a process is the free energy, for a process to be spontaneous, the change in free energy must be negative.
$(\mathbf{R}):$ The change in free energy is related to the change in enthalpy and change in entropy. The change in entropy for a process must be always positive if it is spontaneous.

Hunza Gilgit

Numerade Educator

Problem 177

(A): All exothermic reactions are spontaneous at room temperature.
$(\mathbf{R}):$ In $(\Delta \mathrm{G}=\Delta \mathrm{H}-\mathrm{T} \Delta \mathrm{S}), \Delta \mathrm{G}$ becomes negative
and negative sign of $\Delta \mathrm{G}$ indicates spontaneous reaction.

Hunza Gilgit

Numerade Educator

Problem 178

(A): Endothermic reaction is spontaneous at all temperatures.
$(\mathbf{R}): \Delta \mathrm{G}$ is negative when $\mathrm{T} \Delta \mathrm{S}>\Delta \mathrm{H}$

Hunza Gilgit

Numerade Educator

Problem 179

(A): As temperature increases, heat of reaction also increases for exothermic as well for endothermic reactions.
(R): $\Delta H$ varies with temperatures as given by
$$
\Delta \mathrm{H}_{2}\left(\mathrm{at} \mathrm{T}_{2}\right)=\Delta \mathrm{H}_{1}\left(\mathrm{at} \mathrm{T}_{1}\right)+\Delta \mathrm{C}_{\mathrm{p}}\left(\mathrm{T}_{2}-\mathrm{T}_{1}\right)
$$

Hunza Gilgit

Numerade Educator

Problem 180

(A): Efficiency of a reversible engine is maximum (100\%) when temperature of the sink is $-273^{\circ} \mathrm{C}\left(\mathrm{T}_{1}\right)$
$(\mathbf{R}): \eta($ efficiency $)=\frac{\mathrm{T}_{2}-\mathrm{T}_{1}}{\mathrm{~T}_{2}}$

Hunza Gilgit

Numerade Educator

Problem 181

(A): As solid changes to liquid and then to vapour state, entropy increases.
(R): As going from solid to liquid and then to vapour state, disorder increases.

Hunza Gilgit

Numerade Educator

Problem 182

(A): In the case of an ideal gas, the changes in Gibbs and Helmholtz free energies are equal to each other $(\Delta \mathrm{G}=\Delta \mathrm{A})$ for isothermal reversible processes.
(R): There is no change in internal energies and enthalpies for ideal gases at constant temperature.

Hunza Gilgit

Numerade Educator

Problem 183

(A): When $\mathrm{H}_{2} \mathrm{O}$ is added to $\mathrm{CaO}$, heat is liberated.
(R): Reaction between $\mathrm{CaO}$ and $\mathrm{H}_{2} \mathrm{O}$ is exothermic.

Hunza Gilgit

Numerade Educator

Problem 184

(A): In the following reaction
$$
\begin{aligned}
&\mathrm{C}(\mathrm{s})+\mathrm{O}_{2}(\mathrm{~g}) \rightarrow \mathrm{CO}(\mathrm{g}) \\
&\Delta \mathrm{H}=\Delta \mathrm{E}-\mathrm{RT}
\end{aligned}
$$
$(\mathbf{R}): \Delta \mathrm{H}$ is related to $\Delta \mathrm{E}$ by equation
$$
\Delta \mathrm{H}=\Delta \mathrm{E}+\Delta \mathrm{n}_{\mathrm{g}} \mathrm{RT}
$$

Hunza Gilgit

Numerade Educator

Problem 185

(A): In the following reaction
$$
\mathrm{CO}+1 / 2 \mathrm{O}_{2} \rightarrow \mathrm{CO}_{2}, \Delta \mathrm{H}=-68 \mathrm{kcal}
$$
and thus
$\Delta \mathrm{H}_{\mathrm{f}}\left(\mathrm{CO}_{2}\right)=-68 \mathrm{kcal} \mathrm{mol}^{-1}$
(R): $1 \mathrm{~mol}$ of $\mathrm{CO}_{2}$ is formed and enthalpy change is the heat of formation of $\mathrm{CO}_{2}$.

Hunza Gilgit

Numerade Educator

Problem 186

(A): Heat of neutralization of HF (aq), a weak acid, with $\mathrm{NaOH}$ (aq) is less than $13.7 \mathrm{kcal}$, in an exothermic reaction.
(R): Some heat is lost in the ionization of a weak acid.

Hunza Gilgit

Numerade Educator

Problem 187

(A): The standard enthalpy of formation of graphic is taken as zero but of diamond is not zero but it is equal to $1.816 \mathrm{~kJ} / \mathrm{mol}$.
(R): Among carbon allotropes, diamond is taken as standard state.

Hunza Gilgit

Numerade Educator

Problem 188

(A): In case of some glassy solids having mixture of isotopes, crystals of $\mathrm{CO}, \mathrm{N}_{2} \mathrm{O}, \mathrm{NO}$ etc. entropy is not zero even at absolute zero temperature
(R): These kind of solids do not have perfect order even at absolute zero temperature.

Hunza Gilgit

Numerade Educator

Problem 189

(A): Enthalpy changes are positive when $\mathrm{Na}_{2} \mathrm{SO}_{4}$. $10 \mathrm{H}_{2} \mathrm{O}, \mathrm{CuSO}_{4} \cdot 5 \mathrm{H}_{2} \mathrm{O}$ and salts like $\mathrm{NaCl}, \mathrm{KCl}$
etc. which do not form hydrates are dissolved in water. But enthalpy changes are negative when anhydrous salts capable of forming hydrates are dissolved in water.
(R): The difference in the behaviour is due to large differences in the molecular weights of hydrated and anhydrous salts. The substances with larger molecular weights usually show positive enthalpy change on dissolution.

Hunza Gilgit

Numerade Educator

Problem 190

(A): $\Delta \mathrm{E}$ is state function of the system.
(R): As it depends upon the final and initial state of the system.

Hunza Gilgit

Numerade Educator

Problem 191

(A): In any reversible cycle process, the net increase in entropy of the system is zero.
$(\mathbf{R}):$ As $\Delta S_{\text {unverse }}=\Delta \mathrm{S}_{\text {system }}+\Delta$ Ssurr as in case of reversible cyclic process $\Delta$ Ssystem is positive, but of surrounding is negative in same amount. That is why $\Delta \mathrm{S}_{\text {nivers }}=0$

Hunza Gilgit

Numerade Educator

Problem 192

(A): The enthalpy of neutralization of equivalent of $\mathrm{HF}$ and 1 equivalent $\mathrm{NaOH}$ is $14 \mathrm{kcal} / \mathrm{mol}$. which is higher than $\mathrm{HCl}$ and $\mathrm{NaOH} ?$
$(\mathbf{R}):$ It is because the enthalpy of hydration of $\mathrm{F}^{-}$is higher that of is heat enthalpy of dissociation.

Hunza Gilgit

Numerade Educator

Problem 193

(A): The entropy change in the reaction.
$(\mathbf{R}):$ Entropy increase when no. of particles or (i.e. molecules or ions) of the product or, in the product directions increases.

Hunza Gilgit

Numerade Educator

Problem 194

(A) The amount of work done in the isothermal expansion is greater than work done in the adiabatic system for same final volume.
(R) In the adiabatic expansion of a gas temperature and pressure both decrease due to decrease in internal energy of the system.

Hunza Gilgit

Numerade Educator

Problem 195

(A): There is a natural asymmetry between converting work to heat and converting heat to work.
(R): No process is possible in which the sole result in the absorption of heat from a reservation and its complete conversion into work

Hunza Gilgit

Numerade Educator

Problem 196

Match the following:
List I List II
A. Cyclic process
(p) $\Delta \mathrm{H}$ is positive
B. Spontaneous
(q) $\Delta \mathrm{E}=0, \Delta \mathrm{H}=0$
C. Endothermic
(r) $\Delta \mathrm{G}$ is negative
D. A process in equilib-
(s) $\Delta \mathrm{G}=0$
rium

Himanshu Kushwaha

Himanshu Kushwaha

Numerade Educator

Problem 197

Match the following:
$\begin{array}{ll}\text { List I } & \text { List II }\end{array}$
A. Reversible adiabatic compres-
(p) $\Delta_{\text {Surromding }}<0$ sion
B. Reversible vaporization of
(q) $\Delta_{\text {Surromding }}=0$ liquid
C. $2 \mathrm{~N}(\mathrm{~g}) \rightarrow \mathrm{N}_{2}(\mathrm{~g})$
(r) $\Delta \mathrm{S}_{\text {sytem }}>0$
D. $\mathrm{CaCO}_{3}(\mathrm{~s}) \frac{\Delta}{\mathrm{CaO}(\mathrm{s})+\mathrm{CO}_{2}(\mathrm{~g})}$
(s) $\Delta \mathrm{S}_{\text {system }}<0$

Himanshu Kushwaha

Himanshu Kushwaha

Numerade Educator

Problem 198

Match the following:
$\begin{array}{ll}\text { List I } & \text { List II }\end{array}$
A. Reversible
(p) $w=-\operatorname{RPext} \frac{\left[T_{2} P_{1}-T_{1} P_{2}\right]}{P_{1} P_{2}}$
isothermal expansion
B. Irreversible $\begin{array}{l}\text { isothermal } \\ \text { expansion }\end{array}$ (q) $\left.\mathrm{w}=\frac{\mathrm{R}}{\gamma-1}\left[\mathrm{~T}_{2}-\mathrm{T}_{1}\right]\right]$
C. Reversible adiabatic $\quad$ (r) $w=-\operatorname{Pext}\left(V_{2}-V_{1}\right)$
expansion
D. Irreversible adiabatic $\quad$ (s) $w=-2.303 \mathrm{RT} \log _{10} \mathrm{~V}_{2} / \mathrm{V}_{1}$
expansion

Hunza Gilgit

Numerade Educator

Problem 199

Match the following.
$\begin{array}{ll}\text { List I } & \text { List II }\end{array}$
A. Ice $=\mathrm{H}_{2} \mathrm{O}(l)$ at room tem-
(p) $\Delta H=-v e, \Delta S$
perature $25^{\circ} \mathrm{C}$ $=+$ ve
B. $\mathrm{NH}_{2} \mathrm{COONH}_{4}(\mathrm{~s}) \rightarrow$
(q) $\Delta \mathrm{G}=+\mathrm{ve}$
$2 \mathrm{NH}_{3}(\mathrm{~g})+\mathrm{CO}_{2}(\mathrm{~g})$
(r) $\Delta \mathrm{H}=+\mathrm{ve}, \Delta \mathrm{S}$
C. $2 \mathrm{O}_{3}(\mathrm{~g}) \rightarrow 3 \mathrm{O}_{2}(\mathrm{~g}) \quad=-\mathrm{ve}$
D. $3 \mathrm{O}_{2}(\mathrm{~g}) \rightarrow 2 \mathrm{O}_{3}(\mathrm{~g})$
(s) $\Delta \mathrm{G}=-\mathrm{ve}$

Himanshu Kushwaha

Himanshu Kushwaha

Numerade Educator

Problem 200

Match the following:
$\begin{array}{ll}\text { List I } & \text { List II }\end{array}$
A. Internal energy of $\mathrm{O}_{2}$ gas at $0 \mathrm{~K}$
(i) exothermic $\left(-273^{\circ} \mathrm{C}\right)$
reaction
B. heat of combustion of $\mathrm{N}_{2}$
(ii) $<13.7 \mathrm{Kcal}$
C. heat of neutralization of $\mathrm{HCl}$ and
(iii) 0 $\mathrm{CH}_{3} \mathrm{COOH}$
D. $2 \mathrm{CO}+\mathrm{O}_{2} \rightarrow \mathrm{CO}_{2}$
(iv) $+\mathrm{ve}$

Himanshu Kushwaha

Himanshu Kushwaha

Numerade Educator

Problem 201

Match the following:
List I List II
A. Formation of
(p) Endothermic ammonia
B. Formation of nitric
(q) Exothermic oxide
C. Heat of neutralization of $(\mathrm{r})>13.7 \mathrm{kcal}$ HF
D. Heat of combustion
(s) may be exothermic or endothermic

Himanshu Kushwaha

Himanshu Kushwaha

Numerade Educator

Problem 202

Match the following:
List I List II
A. $\Delta \mathrm{S}$ gas for isothermal of an ideal
(p) $\mathrm{nR} \ln \left(\frac{\mathrm{P}_{1}}{\mathrm{P}_{2}}\right)$
gas
B. Work done in reversible isothermal (q) $-\mathrm{nFE}$ ideal gas expansion
C. $\Delta \mathrm{G}$ for reversible isothermal expan-
(r) $\mathrm{nRT} \ln \left(\frac{\mathrm{P}_{2}}{\mathrm{P}_{1}}\right)$
sion of an ideal gas
D. $\left(\Delta \mathrm{G}_{\text {system }}\right) \mathrm{T}, \mathrm{P}$
(s) $\mathrm{nR} \ln \left(\frac{\mathrm{V}_{2}}{\mathrm{~V}_{\mathrm{1}}}\right)$

Hunza Gilgit

Numerade Educator

Problem 203

Match the following:
List II (Heat of List I $\quad$ neutralization)
A. $\mathrm{H}_{2} \mathrm{SO}_{4}+\mathrm{NaOH}$
(p) $13.7 \mathrm{Kcal}$
B. $\mathrm{H}_{2} \mathrm{SO}_{4}+\mathrm{NH}_{4} \mathrm{OH}$
$(\mathrm{q})>13.7 \mathrm{kcal}$
C. $\mathrm{CH}_{3} \mathrm{COOH}+\mathrm{NH}_{4} \mathrm{OH}$
$(\mathrm{r})<13.7 \mathrm{kcal}$
D. $\mathrm{NaOH}+\mathrm{HF}$
(s) cannot be said

Himanshu Kushwaha

Himanshu Kushwaha

Numerade Educator

Problem 204

Match the following:
List I List II
1. Exothermic substance
(i) Less stable
2. Endothermic substance
(ii) More stable
3. Heat of formation
(iii) Exothermic
(iv) May be exothermic
4. Heat of combustion or endothermic
(v) Endothermic

Himanshu Kushwaha

Himanshu Kushwaha

Numerade Educator

Problem 204

Anhydrous $\mathrm{AlCl}_{3}$ is covalent. From the data given below, predict whether it would remain covalent or become ionic in aqueous solution (ionization energy of $\mathrm{Al}=5137 \mathrm{~kJ} \mathrm{~mol}^{-1}, \Delta \mathrm{H}_{\text {htrim }}$ for $\mathrm{Al}^{+3}=-4665 \mathrm{~kJ}$
$\mathrm{mol}^{-1}, \Delta \mathrm{H}_{\text {hytration }}$ for $\left.\mathrm{Cl}^{-}=-381 \mathrm{~kJ} \mathrm{~mol}^{-1}\right)$
a. ionic
b. covalent
c. both
d. none [IIT 1997]

Hunza Gilgit

Numerade Educator

Problem 205

Molar heat capacity of water in equilibrium with ice at constant pressure is
a. zero
b. infinity
c. $40.45 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}$
d. $75.48 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}$
[IIT 1997]

Himanshu Kushwaha

Himanshu Kushwaha

Numerade Educator

Problem 205

Molar heat capacity of water in equilibrium with ice at constant pressure is
a. zero
b. infinity
c. $40.45 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}$
d. $75.48 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}$
[IIT 1997]

Hunza Gilgit

Numerade Educator

Problem 206

Standard molar enthalpy of formation of $\mathrm{CO}_{2}$ is equal to
a. zero
b. the standard molar enthalpy of combustion of gaseous carbon.
c. the sum of standard molar enthalpies of formation of $\mathrm{CO}$ and $\mathrm{CO}_{2}$
d. the standard molar enthalpy of combustion of carbon (graphite) [IIT 1997]

Hunza Gilgit

Numerade Educator

Problem 206

Standard molar enthalpy of formation of $\mathrm{CO}_{2}$ is equal to
a. zero
b. the standard molar enthalpy of combustion of gaseous carbon.
c. the sum of standard molar enthalpies of formation of $\mathrm{CO}$ and $\mathrm{CO}_{2}$
d. the standard molar enthalpy of combustion of carbon (graphite) [IIT 1997]

Hunza Gilgit

Numerade Educator

Problem 207

The enthalpy change involved in the oxidation of glucose is $-2880 \mathrm{~kJ} \mathrm{~mol}^{-1}$. Twenty five percent of this energy is available for muscular work. If 100 $\mathrm{kJ}$ of muscular work is needed to walk one kilometer, what is the maximum distance that a person will be able to walk eating $120 \mathrm{~g}$ of glucose?
a. $7.9 \mathrm{~km}$
b. $9.7 \mathrm{~km}$
c. $4.8 \mathrm{~km}$
d. $8.4 \mathrm{~km}$
[IIT 1997]

Hunza Gilgit

Numerade Educator

Problem 207

The enthalpy change involved in the oxidation of glucose is $-2880 \mathrm{~kJ} \mathrm{~mol}^{-1}$. Twenty five percent of this energy is available for muscular work. If 100 $\mathrm{kJ}$ of muscular work is needed to walk one kilometer, what is the maximum distance that a person will be able to walk eating $120 \mathrm{~g}$ of glucose?
a. $7.9 \mathrm{~km}$
b. $9.7 \mathrm{~km}$
c. $4.8 \mathrm{~km}$
d. $8.4 \mathrm{~km}$
[IIT 1997]

Hunza Gilgit

Numerade Educator

Problem 208

Anhydrous $\mathrm{AlCl}_{3}$ is covalent. From the data given below, predict whether it would remain covalent or become ionic in aqueous solution (ionization energy of $\mathrm{Al}=5137 \mathrm{~kJ} \mathrm{~mol}^{-1}, \Delta \mathrm{H}_{\text {htrim }}$ for $\mathrm{Al}^{+3}=-4665 \mathrm{~kJ}$
$\mathrm{mol}^{-1}, \Delta \mathrm{H}_{\text {hytration }}$ for $\left.\mathrm{Cl}^{-}=-381 \mathrm{~kJ} \mathrm{~mol}^{-1}\right)$
a. ionic
b. covalent
c. both
d. none [IIT 1997]

Hunza Gilgit

Numerade Educator

Problem 209

Calculate the enthalpy change for the combustion of cyclopropane at $298 \mathrm{~K}$, if the enthalpy of formation $\mathrm{CO}_{2}(\mathrm{~g}), \mathrm{H}_{2} \mathrm{O}(l)$ and propene $(\mathrm{g})$ are $-393.5,-385.8$ and $20.42 \mathrm{~kJ} \mathrm{~mol}^{-1}$ respectively. The enthalpy of isomerization of cyclopropane to propene is $-33.0$ $\mathrm{kJ} \mathrm{mol}^{-1}$.
a. $1802 \mathrm{~kJ} \mathrm{~mol}^{-1}$
b. $2091 \mathrm{~kJ} \mathrm{~mol}^{-1}$
c. $2196 \mathrm{~kJ} \mathrm{~mol}^{-1}$
d. none [IIT 1998]

Hunza Gilgit

Numerade Educator

Problem 210

Which of the following is not an endothermic reactions?
a. combustion of methane
b. decomposition of water
c. dehydrogenation of ethane or ethylene
d. conversion of graphite to diamond [IIT 1999]

Hunza Gilgit

Numerade Educator

Problem 211

The $\Delta \mathrm{H}_{\mathrm{f}}^{\mathrm{o}}$ for $\mathrm{CO}_{2}(\mathrm{~g}), \mathrm{CO}(\mathrm{g})$ and $\mathrm{H}_{2} \mathrm{O}(\mathrm{g})$ are $-393.5$,
$-110.5$ and $-241.8 \mathrm{~kJ} \mathrm{~mol}^{-1}$ respectively. The standard enthalpy change (in $\mathrm{kJ}$ ) for the reaction
$\mathrm{CO}_{2}(\mathrm{~g})+\mathrm{H}_{2}(\mathrm{~g}) \rightarrow \mathrm{CO}(\mathrm{g})+\mathrm{H}_{2} \mathrm{O}(\mathrm{g})$ is
a. $524.1$
b. $41.2$
c. $-262.5$
d. $-41.2$ [IIT 2000]

Himanshu Kushwaha

Himanshu Kushwaha

Numerade Educator

Problem 212

Which of the following statement is false?
a. work is a state function
b. temperature is a state function
c. change of state is completely defined when initial and final states are specified.
d. work appears at the boundary of the solution. [IIT 2001]

Hunza Gilgit

Numerade Educator

Problem 213

In thermodynamics, a process is called reversible when
a. surroundings and system change into each other
b. there is no boundary between system and surroundings
c. the surroundings are always in equilibrium with the system
d. the system changes into the surroundings spontaneously [IIT 2001]

Hunza Gilgit

Numerade Educator

Problem 214

One mole of a non-ideal gas undergoes a change of state $(2.0 \mathrm{~atm}, 3.0 \mathrm{~L}, 95 \mathrm{~K}) \rightarrow(4.0 \mathrm{~atm}, 5.0 \mathrm{~L}, 245 \mathrm{~K})$
with a change in internal energy, $\Delta \mathrm{U}=30.0 \mathrm{~L}$ atm. The change in enthalpy $(\Delta \mathrm{H})$ of the process in $\mathrm{L}$ atm is
a. $40.0$
b. $42.3$
c. $44.0$
d. not defined, because pressure is not constant
[IIT 2002]

Himanshu Kushwaha

Himanshu Kushwaha

Numerade Educator

Problem 215

Which of the following reaction defines $\Delta \mathrm{H}^{\circ}$ ?
a. $\mathrm{C}$ (diamond) $+\mathrm{O}_{2}(\mathrm{~g}) \rightarrow \mathrm{CO}_{2}(\mathrm{~g})$
b. $1 / 2 \mathrm{H}_{2}(\mathrm{~g})+1 / 2 \mathrm{~F}_{2}(\mathrm{~g}) \rightarrow \mathrm{HF}(\mathrm{g})$
c. $\mathrm{N}_{2}(\mathrm{~g})+3 \mathrm{H}_{2}(\mathrm{~g}) \rightarrow 2 \mathrm{NH}_{3}(\mathrm{~g})$
d. $\mathrm{CO}(\mathrm{g})+1 / 2 \mathrm{O}_{2}(\mathrm{~g}) \rightarrow \mathrm{CO}_{2}(\mathrm{~g})$
[IIT 2003]

Himanshu Kushwaha

Himanshu Kushwaha

Numerade Educator

Problem 216

Two mole of an ideal gas is expanded isothermally and reversibly from 1 litre of 10 litre at $300 \mathrm{~K}$. The enthalpy change (in $\mathrm{kJ}$ ) for the process is
a. $11.4 \mathrm{~kJ}$
b. $-11.4 \mathrm{~kJ}$
c. $0 \mathrm{~kJ}$
d. $4.8 \mathrm{~kJ}$.
[IIT 2004]

Himanshu Kushwaha

Himanshu Kushwaha

Numerade Educator

Problem 217

The enthalpy of vapourization of a liquid is $30 \mathrm{~kJ}$ $\mathrm{mol}^{-1}$ and entropy of vapourization is $5 \mathrm{~J} \mathrm{~mol}^{-1} \mathrm{~K}$. The boiling point of the liquid at 1 atm is
a. $250 \mathrm{~K}$
b. $400 \mathrm{~K}$
c. $450 \mathrm{~K}$
d. $600 \mathrm{~K}$
[IIT 2004]

Himanshu Kushwaha

Himanshu Kushwaha

Numerade Educator

Problem 218

One mole of monatomic ideal gas at $\mathrm{T}(\mathrm{K})$ is expanded from $1_{1}$ to 2 , adiabatically under a constant external pressure of 1 atm the final temperature of the gas in Kelvin is
a. $\mathrm{T}$
b. $\mathrm{T} / 2^{5 / 3-1}$
c. $\mathrm{T}-\frac{2}{3 \times 0.0821}$
d. $\mathrm{T}+\frac{3}{2 \times 0.0821}$

Himanshu Kushwaha

Himanshu Kushwaha

Numerade Educator

Problem 219

For the reaction, $2 \mathrm{CO}+\mathrm{O}_{2} \rightarrow 2 \mathrm{CO}_{2}, \Delta \mathrm{H}=-560 \mathrm{~kJ}$.
Two moles of $\mathrm{CO}$ and one mole of $\mathrm{O}_{2}$ are taken in a container of volume $1 \mathrm{~L}$. They completely form two moles of $\mathrm{CO}_{2}$, the gases deviate appreciably from ideal behaviour. If the pressure in the vessel changes from 70 to $40 \mathrm{~atm}$, find the magnitude (absolute value) of $\Delta \mathrm{U}$ at $500 \mathrm{~K}$.
(1 L atm $=0.1 \mathrm{~kJ})$
a. $557 \mathrm{KJ}$
b. $55.7 \mathrm{KJ}$
c. $278 \mathrm{KJ}$
d. $27.8 \mathrm{KJ}$
[IIT 2006]

Himanshu Kushwaha

Himanshu Kushwaha

Numerade Educator

Problem 220

The direct conversion of $\mathrm{A}$ to $\mathrm{B}$ is difficult, hence it is carried out by the following shown path:
Given $\Delta S_{(\Lambda \rightarrow C)}=50$ e.u
$\Delta \mathrm{S}_{(\mathrm{C} \rightarrow \mathrm{D})}=30 \mathrm{e} . \mathrm{u}$
$\Delta \mathrm{S}_{(\mathrm{B} \rightarrow \mathrm{D})}=20 \mathrm{e} . \mathrm{u}$
where e.u. is entropy unit then $\Delta \mathrm{S}(\mathrm{A} \rightarrow \mathrm{B})$ is
a. $+100 \mathrm{e} . \mathrm{u}$.
b. $+60 \mathrm{e} . \mathrm{u}$.
c. $-100$ e.u.
d. $-60$ e.u.

Himanshu Kushwaha

Himanshu Kushwaha

Numerade Educator

Problem 221

For the process $\mathrm{H}_{2} \mathrm{O}$ (I) $(1 \mathrm{bar}, 373 \mathrm{~K}) \rightarrow \mathrm{H}_{2} \mathrm{O}(\mathrm{g})(1 \mathrm{bar}, 373 \mathrm{~K})$
the correct set of thermodynamic parameters is
a. $\Delta \mathrm{G}=0, \Delta \mathrm{S}=+\mathrm{ve}$
b. $\Delta \mathrm{G}=0, \Delta \mathrm{S}=-\mathrm{ve}$
c. $\Delta \mathrm{G}=+\mathrm{ve}, \Delta \mathrm{S}=0$
d. $\Delta \mathrm{G}=-\mathrm{ve}, \Delta \mathrm{S}=+\mathrm{ve}$
[IIT 2007]

Himanshu Kushwaha

Himanshu Kushwaha

Numerade Educator

Problem 222

The value of $\log _{10} \mathrm{~K}$ for a reaction $\mathrm{A} \rightleftharpoons \mathrm{B}$ is (Given: $\Delta$. $\mathrm{H}_{29 \mathrm{~K}}^{\mathrm{o}}=-54.07 \mathrm{~kJ} \mathrm{~mol}^{-1}, \Delta_{\mathrm{r}} \mathrm{S}_{299 \mathrm{~K}}^{0}=10 \mathrm{JK}^{-1} \mathrm{~mol}^{-1}$ and
$\left.\mathrm{R}=8.314 \mathrm{JK}^{-1} \mathrm{~mol}^{-1} ; 2.303 \times 8.314 \times 298=5705\right)$
a. 10
b. 100
c. 5
d. 95 [IIT 2007]

Himanshu Kushwaha

Himanshu Kushwaha

Numerade Educator

Problem 223

In a constant volume calorimeter, $3.5$ of a gas with molecular weight 28 was burnt in excess oxygen at $298.0 \mathrm{~K}$ The temperature of the calorimeter was found to increase from $298.0 \mathrm{~K}$ to $298.45 \mathrm{~K}$ due to the combustion process. Given that the heat capacity of the calorimeter is $2.5 \mathrm{~kJ} \mathrm{~K}^{-1}$, the numerical value for the enthalpy of combustion of the gas in $\mathrm{kJ} \mathrm{mol}^{-1}$ is
a. 10
b. 100
c. 5
d. 95 [IIT 2009]

Hunza Gilgit

Numerade Educator