Chapter 9, Hydrogen Video Solutions, NCERT at you Fingerstips: Chemistry

Chapter Questions

Problem 1

In what respect electronic configuration of hydrogen are similar? and halogens are sind halogens have one electron in
(a) Hydrogen their outermost shell. and halogens have one electron less
(b) Hydrogen than the noble gas configuration. and halogens can lose one electron
(c) Hydrogen to form positive ions.
(d) Hydrogen and halogens show noble gas configuration.

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Problem 2

Which of the following properties of hydrogen is incorrect?
(a) Like halogens, hydrogen exists as a diatomic
gas.
(b) Like halogens, hydrogen exhibits $-1$ oxidation state in its compounds with metals.
(c) Like halogens, hydrogen is liberated at cathode.
(d) The ionisation energy of hydrogen is quite close to halogens.

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Problem 3

In which of the following properties hydrogen does not show similarity with alkali metals?
(a) Electropositive character
(b) Reducing nature
(c) Electronic configuration (ns')
(d) Diatomic nature of molecule

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Problem 4

A deuterium is
(a) an electron with a positive charge
(b) a nucleus having two protons
(c) a nucleus containing a neutron and two protons
(d) a nucleus containing a neutron and a proton.

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Problem 5

Which of the following is not an isotope of hydrogen?
(a) Protium
(b) Ortho- para hydrogen
(c) Deuterium
(d) Tritium

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Problem 6

Which of the following is an atom of tritium?

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Problem 7

The isotopes of hydrogen have different physical properties due to difference in mass. They have almost same chemical properties with a difference in their rates of reactions which is mainly due to
(a) their different enthalpy of bond dissociation
(b) different electronic configurations
(c) different atomic masses
(d) different physical properties.

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Problem 8

Which of the following metals will react with $\mathrm{NaOH}$ and $\mathrm{KOH}$ to liberate hydrogen gas?
(a) $\mathrm{Zn}, \mathrm{Al}, \mathrm{Fe}$ and $\mathrm{Mg}$
(b) Al, Fe, $\mathrm{Mg}$ and $\mathrm{Sn}$
(c) $\mathrm{Zn}, \mathrm{Sn}$ and $\mathrm{Al}$
(d) $\mathrm{Fe}, \mathrm{Mg}$ and $\mathrm{Al}$

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Problem 9

Which of the following metals does not liberate hydrogen from acids?
(a) $\mathrm{Fe}$
(b) $\mathrm{Cu}$
(c) $\mathrm{Mg}$
(d) $\mathrm{Zn}$

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Problem 10

A metal which does not react with cold water but reacts with steam to liberate $\mathrm{H}_{2}$ gas is
(a) $\mathrm{Na}$
(b) $\mathrm{Mg}$
(c) Au
(d) $\mathrm{Fe}$

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Problem 11

Pure nascent hydrogen is best obtained by
(a) $\mathrm{Na}$ and $\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}$
(b) $\mathrm{A}$ and $\mathrm{NOH}$
(c) $\mathrm{Zn}$ and dil $\mathrm{H}_{2} \mathrm{SO}_{4}$
(d) all of these.

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Problem 12

Which of the following is baboratory preparation of dilhydrogen?
(a) $3 \mathrm{Fe}+4 \mathrm{H}_{2} \mathrm{O}$ (steam) $\rightarrow \mathrm{Fe}_{3} \mathrm{O}_{4}+4 \mathrm{H}_{2}$
(b) $2 \mathrm{Na}+2 \mathrm{H}_{2} \mathrm{O} \rightarrow 2 \mathrm{NaOH}+\mathrm{H}_{2}$
(c) $\mathrm{CaH}_{2}+2 \mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{Ca}(\mathrm{OH})_{2}+2 \mathrm{H}_{2}$
(d) $\mathrm{Zn}+\mathrm{H}_{2} \mathrm{SO}_{4}$ (dil) $\rightarrow \mathrm{ZnSO}_{4}+\mathrm{H}_{2}$

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Problem 13

The proces of production of syngas from sewage, \mathrm{\{} A w - d u s t , ~ s c r a p ~ w o o d , ~ e t c . ~ i s ~ q u i t e ~ c o m m o n ~ t h e s e ~
days. The production of syngas from coal is called
(a) carbonination
(b) water gas shift
(c) coal gasification
(d) synthesis gas shift.

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Problem 14

Syngas is a mixture of
(a) $\mathrm{CO}_{2}+\mathrm{H}_{2}$
(b) $\mathrm{CO}+\mathrm{H}_{2}$
(c) $\mathrm{CO}+\mathrm{CO}_{2}$
(d) $\mathrm{CO}+\mathrm{O}_{2}$

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Problem 15

The production of dihydrogen obtained from coal gasification can be increased by reacting carbon monoxide of syngas mixture with steam in presence of a catalyst iron chromate. What is this process called?
(a) Hydrogen reaction
(b) Water-gas shift reaction
(c) Coal-gas shift reaction
(d) Syn gasification

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Problem 16

Water gas is mixed with steam and the mixture is passed over heated $\mathrm{Fe}_{2} \mathrm{O}_{3}$ in presence of $\mathrm{Cr}_{2} \mathrm{O}_{3}$. The mixture when passed in water dissolves $\mathrm{CO}_{2}$ and dihydrogen left undissolved is collected. This method of preparation of hydrogen gas is known as
(a) Bosch process
(b) Lane process
(c) Kellner process
(d) Hall process

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Problem 17

Which of the following is not a property of hydrogen?
(a) It is a colourless, odourless gas.
(b) It is highly combustible.
(c) It is highly poisonous gas.
(d) It is lighter than air.

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Problem 18

If a mole of hydrogen molecule is heated to a high temperature then which of the following reactions take place?
(a) $\mathrm{H}_{2(g)}+436 \mathrm{~kJ} \mathrm{~mol}^{-1} \rightarrow \mathrm{H}_{(g)}+\mathrm{H}_{(g)}$
(b) $2 \mathrm{H}_{2(g)}+820 \mathrm{~kJ} \mathrm{~mol}^{-1} \rightarrow 2 \mathrm{H}_{2(g)}$
(c) $\mathbf{H}_{2(g)}+\mathbf{H}_{2(\phi)}+436 \mathrm{~kJ} \mathrm{~mol}^{-1} \rightarrow \mathrm{H}_{(\infty)}^{+}+\mathrm{H}_{(\alpha q)}^{-}$
(d) $\mathrm{H}_{2(\mathrm{~d}}+200 \mathrm{~kJ} \mathrm{~mol}^{-1} \rightarrow \mathrm{H}_{(\mathfrak{q})}+\mathrm{H}_{(\mathrm{g})}$

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Problem 19

Which of the following statements is corred? regurding hydrogen?
(a) Hydrogen shows $+1$ and $-1$ oxidation ttatey
(b) Hydrogen is never liberated at anode
(c) Hydrogen has same ionisation enthalpy as thaz of alkali metals.
(d) Hydrogen has same electronegativity as of halogens.

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Problem 20

The order of reactivity of halogens towards hydrogen is
(a) $\mathrm{F}_{2}>\mathrm{Cl}_{2}>\mathrm{Br}_{2}>\mathrm{I}_{2}$
(b) $\mathrm{I}_{2}>\mathrm{Br}_{2}>\mathrm{Cl}_{2}>\mathrm{F}_{3}$
(c) $\mathrm{Cl}_{2}>\mathrm{Br}_{2}>\mathrm{I}_{2}>\mathrm{F}_{2} \quad$ (d) $\mathrm{Br}_{2}>\mathrm{Cl}_{2}>\mathrm{F}_{2}>1 .$

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Problem 21

Hydrogen burns in air with a
(a) light bluish flame (b) yellow flame
(c) crimson red flame (d) green flame.

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Problem 22

Which of the following reactions of hydrogen with non-metals represents Haber's process?
(a) $2 \mathrm{H}_{2}+\mathrm{O}_{2} \stackrel{\mathrm{hen}}{\longrightarrow} 2 \mathrm{H}_{2} \mathrm{O} ; \Delta H=-285.9 \mathrm{k} \mathrm{J} \mathrm{mol}^{-1}$
(b) $3 \mathrm{H}_{2}+\mathrm{N}_{2} \frac{673 \mathrm{~K}, \mathrm{Fe}}{200 \mathrm{~atm}} 2 \mathrm{NH}_{3} ; \Delta H=-92.6 \mathrm{~kJ} \mathrm{~mol}^{-1}$
(c) $\mathrm{H}_{2}+\mathrm{Cl}_{2} \stackrel{\mathrm{hv}}{\longrightarrow} 2 \mathrm{HCl}$
(d) $2 \mathrm{H}_{2}+\mathrm{C} \stackrel{1100^{\circ} \mathrm{C}}{\rightarrow} \mathrm{CH}_{4}$

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Problem 23

Which of the following metals directly combine with hydrogen gas to give a hydride?
(a) Au (b) $\mathrm{Ni} \quad$ (c) $\mathrm{Ca}$ (d) $\mathrm{Cu}$

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Problem 24

Which property of hydrogen is shown by the following reactions?
(i) $\mathrm{Fe}_{3} \mathrm{O}_{4}+4 \mathrm{H}_{2} \rightarrow 3 \mathrm{Fe}+4 \mathrm{H}_{2} \mathrm{O}$
(ii) $\mathrm{CO}+\mathrm{H}_{2} \stackrel{\mathrm{ZnO},}{\mathrm{Cr}_{2} \mathrm{O}_{3}} \mathrm{CH}_{3} \mathrm{OH}$
(a) Reducing character (b) Oxidising character
(c) Combustibility
(d) High reactivity

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Problem 25

A metal $(M)$ produces a gas $(N)$ on reaction with alkalies like $\mathrm{NaOH}$ and $\mathrm{KOH}$. Same gas is produced when the metal reacts with dilute sulphuric acid Gas $(N)$ reacts with another toxic gas $(P)$ to form methanol at high temperature and pressure. ( $N$ ) also reacts with metals like $(Q)$ to form electrovalent hydrides. $M, N, P$ and $Q$ respectively are
(a) $\mathrm{Zn}, \mathrm{H}_{2}, \mathrm{CO}, \mathrm{Na}$
(b) $\mathrm{Na}, \mathrm{H}_{2}, \mathrm{Cl}_{2}, \mathrm{Ca}$
(c) $\mathrm{Al}, \mathrm{H}_{2}, \mathrm{H}_{2} \mathrm{~S}, \mathrm{~B}$
(d) $\mathrm{Mg}, \mathrm{H}_{2}, \mathrm{NO}_{2}, \mathrm{Al}$

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Problem 26

Alkenes combine with carbon monoxide and hydrogen in presence of octacarbonyldicobalt as catalyst under high temperature and pressure to form
(a) aldehydes which can be further reduced to alcohols by hydrogen
(b) alkanes which are formed by addition of hydrogen

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Problem 27

What is trend of boting points of budrudes or $x$, w $-x$ the
Due to lower lower boting pounts than those of the
(1) HF bave lower bomets? gobsequent group memluer Due to higher electronegativiry
(b)
$\mathrm{F}, \mathrm{NH}_{3}, \mathrm{H}_{2} \mathrm{O}$ and HF inow hvdrogen bonding
and bence bigher bouing points than the bratides of their subsequent group members. There is no regular trend in the boding points
(d) Due to higher oxidation states of $\mathrm{N}, \mathrm{O}$ and $\mathrm{F}_{\text {, }}$ (d) boiling points of $\mathrm{NH}_{3}, \mathrm{H}_{2} \mathrm{O}$ and HF are than the hydrides of their subsequent higher thanbers. group members.

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Problem 28

On mooing from left to right in a period what is the order of acidic character of hydrides?
(a) $\mathrm{NH}_{3}<\mathrm{H}_{2} \mathrm{O}<\mathrm{HF}$
(b) $\mathrm{HF}<\mathrm{H}_{2} \mathrm{O}<\mathrm{NH}_{3}$
(c) $\mathrm{H}_{2} \mathrm{O}<\mathrm{HF}<\mathrm{NH}_{3}$
(d) $\mathrm{H}_{2} \mathrm{O}<\mathrm{NH}_{3}<\mathrm{HF}$

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Problem 29

In complex hydrides, hydride ions act as ligand and are coordinated to metal ions. These hydrides are good reducing agents. Which of the following bydrides is not a complex hvdride?
(a) LiAIH $_{4}$
(b) $\mathrm{NaBH}_{4}$
(c) $\left(\mathrm{AlH}_{3}\right)_{=}$
(d) $\mathrm{LiBH}_{4}$

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Problem 30

Which of the following hydrides is electron deficient?
(a) $\mathrm{NaH}$
(b) $\mathrm{CaH}_{2}$
(c) $\mathrm{CH}_{4}$
(d) $\mathrm{B}_{2} \mathrm{H}_{6}$

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Problem 31

Which of the following statements regarding hydrides is not correct?
(a) lonic hydrides are crystalline, non-volatile and non-conducting in solid state.
(b) Electron-deficient hydrides act as Lewis acids or electron acceptors.
(c) Elements of group-13 form electron-deficient hydrides.
(d) Elements of group $15-17$ form electron-precise hydrides.

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Problem 32

Dihydrogen forms three types of hydrides. (i) bydrides are formed by alkali metals and alkaline earth metals, (ii) hydrides are formed by non-metals and (iii) hydrides are formed by $d$ and $f$-block

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Problem 33

Carton bydrides of the trpe, $C_{1} H_{2 x-z}$ do mot act as Lewis acid or Lewis base Ther behme as normal covalent bydrides becanse
(a) carbon hudrides are eletron-rich Erdrides
(b) carbon trudrides are electron-deficiert britrides
(c) carton hydrides are electron-precise hodrides
(d) carbon hodrides are non-stoichionetric hydrides.

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Problem 34

From group 6 coly oce meal forms trydride This metal is
(a) $\mathrm{Mo}$
(b) $\mathrm{W}$
(c) $\mathrm{Cr}$
(d) $\mathrm{Co}$

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Problem 35

Phosphoras cannot form $\mathrm{PH}_{5}$ with its outer electronic configuration as $30^{2} 3 p^{3}$ becanse
(a) phosphorus cannot show $+5$ oridation state
(b) $\mathrm{PH}_{5}$ is not a stable compound
(c) $\mathrm{A}_{2} \mathrm{H}$ value of dihydrogen and $\mathbf{A}_{4} \mathrm{H}$ value of hydrogen do not favour higher oridation state of phosphorus
(d) phosphorus is not rery reactive hence does not form $\mathrm{PH}_{5}$

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Problem 36

Among $\mathrm{NH}_{3}, \mathrm{H}_{2} \mathrm{O}, \mathrm{HF}$ and $\mathrm{H}_{2} \mathrm{~S}$ which would have
highest magnitude of hydrogen bonding?
(a) HF due to maximum pobrity.
(b) $\mathrm{H}_{2} \mathrm{O}$ due to lone pairs of electrons.
(c) $\mathrm{NH}_{3}$ due to small size of nitrogen.
(d) $\mathrm{H}_{2} \mathrm{~S}$ due to higher electron affinity of sulphur

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Problem 37

Non-stoichiometric hydrides are produced by
(a) palladium, vanadium
(b) manganese, lithium
(c) nitrogen, fuorine
(d) carbon, nickel

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Problem 38

Match the column I with column II and mark the appropriate choice.
(a) (A) $\rightarrow($ iii), $(B) \rightarrow($ iv $),(C) \rightarrow$ (ii) $(D) \rightarrow($ i $)$
(b) $(\mathbf{A}) \rightarrow(\mathrm{ii}),(\mathrm{B}) \rightarrow(\mathrm{iv}),(\mathrm{C}) \rightarrow(\mathrm{iii}),(\mathrm{D}) \rightarrow(\mathrm{i})$
(c) $(\mathrm{A}) \rightarrow(\mathrm{i}),(\mathrm{B}) \rightarrow(\mathrm{ii}),(\mathrm{C}) \rightarrow(\mathrm{iv}),(\mathrm{D}) \rightarrow(\mathrm{iii})$
(d) $(\mathrm{A}) \rightarrow(\mathrm{iii}),(\mathrm{B}) \rightarrow$ (ii), (C) $\rightarrow(\mathrm{i}),(\mathrm{D}) \rightarrow$ (iv)

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Problem 39

Given below are the elements and the type of hydrides formed by them. Mark the incorrect match.
(a) Phosphorus-Molecular hydride
(b) Potassium-Ionic hydride
(c) Vanadium-Interstitial hydride
(d) Nitrogen-Electron-deficient covalent hydride

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Problem 40

Liquid water is denser than ice due to
(a) higher surface tension
(b) hydrogen bonding
(c) van der Waals forces
(d) covalent bonding.

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Problem 41

The density of water is less in its solid state because
(a) in solid state (ice), water molecules are arranged in highly ordered open cage like structure
(b) more extensive hydrogen bonding is present in solid state ice
(c) the water molecules are closest in solid state of water
(d) water is a rigid crystalline, closely packed structure in its solid state.

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Problem 42

Water plays a key role in the biosphere. It is due to certain properties of $\mathrm{H}_{2} \mathrm{O}$ as compared to other liquids. These are except
(a) higher specific heat
(b) lesser thermal conductivity
(c) high dielectric constant
(d) high surface tension.

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Problem 43

The $\mathrm{H}-\mathrm{O}-\mathrm{H}$ angle in water molecule is about
(a) $90^{\circ}$
(b) $180^{\circ}$
(c) $102^{\circ}$
(d) $105^{\circ}$

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Problem 44

Choose the correct statement about the given figures.
(a) (II) represents solid state while (III) represents liquid state.
(b) (II) represents liquid state while (III) represents solid state.
(c) (I) represents solid state while (III) represents liquid state.
(d) (I) represents liquid state while (III) represents solid state.

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Problem 45

Which is not a property of water?
(a) It is a colourless and tasteless liquid.
(b) There is no hydrogen bonding in solid state of water.
(c) It is an excellent solvent for transportation of ions in plants and animals.
(d) Frozen water is lighter than liquid water.

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Problem 46

Which of the statements given below are true for the structure of water molecule?
(i) Oxygen undergoes sp ${ }^{3}$ hybridisation.
(ii) Due to presence of two lone pairs of electrons on oxygen the $\mathrm{H}-\mathrm{O}-\mathrm{H}$ bond angle is $118.4^{\circ}$
(iii) Due to angular geometry the net dipole moment of water is not zero, $\mu=1.84 \mathrm{D}$.
(a) (i) and (ii)
(b) (ii) and (iii)
(c) (i) and (iii)
(d) only (ii)

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Problem 47

The maximum number of hydrogen bonds formed by a water molecule in ice is
(a) 4
(b) 1
(c) 2
(d) 3

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Problem 48

In which of the following reactions $\mathrm{H}_{2} \mathrm{O}$ acts as a Bronsted acid?
(a) $\mathrm{H}_{2} \mathrm{O}_{(1)}+\mathrm{NH}_{3(a q)} \rightleftharpoons \mathrm{OH}_{(a q)}^{-}+\mathrm{NH}_{4(\mathrm{aq})}^{+}$
(b) $\mathrm{H}_{2} \mathrm{O}_{(\mathrm{D})}+\mathrm{H}_{2} \mathrm{~S}_{(a q)} \rightleftharpoons \mathrm{H}_{3} \mathrm{O}_{(a q)}^{+}+\mathrm{HS}_{(a q)}^{-}$
(c) $\mathrm{H}_{2} \mathrm{O}_{(l)}+\mathrm{H}_{2} \mathrm{O}_{(D)} \rightleftharpoons \mathrm{H}_{3} \mathrm{O}_{(\mathrm{aq})}^{+}+\mathrm{OH}^{-}_{(a q)}$
(d) $\mathrm{H}^{+}{ }_{(a q)}+\mathrm{OH}^{-}_{(a q)} \rightleftharpoons \mathrm{H}_{2} \mathrm{O}_{(l)}$

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Problem 49

What is the below, called? reaction given
$\mathrm{H}_{2} \mathrm{O}_{(\mathrm{l})}+$ $\mathrm{H}_{2} \mathrm{O}_{(l)}$ $\rightleftharpoons \mathrm{H}_{3} \mathrm{O}_{(a q)}^{+}+\mathrm{OH}^{-}(a q)$
Hydrolysis of
(a) Hydration
(b) Hyarationation of water (c) Disproportionatis of water (d) Auto-protolysis

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Problem 50

Match the reactions of column I with their types given in column II and mark the appropriate choice.
(a) (A) $\rightarrow$ (ii), (B) $\rightarrow$ (i), (C) $\rightarrow$ (iii), (D) $\rightarrow$ (iv)
(b) $(\mathrm{A}) \rightarrow$ (iii), (B) $\rightarrow$ (ii), (C) $\rightarrow$ (iv), (D) $\rightarrow$ (i)
(c) (A) $\rightarrow$ (i), (B) $\rightarrow$ (ii), (C) $\rightarrow$ (iv), (D) $\rightarrow$ (iii)
(d) $(\mathrm{A}) \rightarrow$ (iii), (B) $\rightarrow$ (iv), (C) $\rightarrow$ (i), (D) $\rightarrow$ (ii)

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Problem 51

Given below are two reactions of water with sodium and carbon dioxide. What is the nature of water in these reactions?
(i) $2 \mathrm{Na}+2 \mathrm{H}_{2} \mathrm{O} \rightarrow 2 \mathrm{NaOH}+\mathrm{H}_{2}$
(ii) $6 \mathrm{CO}_{2}+12 \mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6}+6 \mathrm{H}_{2} \mathrm{O}+6 \mathrm{O}_{2}$
(a) In (ii) water acts as an oxidising agent and in
(i) it acts as a reducing agent.
(b) In (i) water acts as an oxidising agent while in
(ii) it acts as a reducing agent.
(c) In both, (i) and (ii) hydrogen acts as a reducing agent.
(d) In both,
(i) and
(ii) hydrogen acts as an oxidising agent.

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Problem 52

Which of the following reactions shows reduction of water?
(a) $2 \mathrm{H}_{2} \mathrm{O}+2 \mathrm{Na} \rightarrow 2 \mathrm{NaOH}+\mathrm{H}_{2}$
(b) $6 \mathrm{CO}_{2}+12 \mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6}+6 \mathrm{H}_{2} \mathrm{O}+6 \mathrm{O}_{2}$
(c) $2 \mathrm{~F}_{2}+2 \mathrm{H}_{2} \mathrm{O} \rightarrow 4 \mathrm{H}^{+}+4 \mathrm{~F}^{-}+\mathrm{O}_{2}$
(d) $\mathrm{P}_{4} \mathrm{O}_{10}+6 \mathrm{H}_{2} \mathrm{O} \rightarrow 4 \mathrm{H}_{3} \mathrm{PO}_{4}$

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Problem 53

Hydrolysis of $\mathrm{SiCl}_{4}$ gives
(a) $\mathrm{Si}(\mathrm{OH})_{4}$
(b) $\mathrm{SiOCl}_{2}$
(c) $\mathrm{SiO}_{2}$
(d) $\mathrm{H}_{2} \mathrm{SiO}_{4}$

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Problem 54

Fluorine decomposes cold water to give
(a) $4 \mathrm{H}^{+}+4 \mathrm{~F}^{-}$and $\mathrm{O}_{2}$
(b) $\mathrm{HF}$ and $\mathrm{H}_{2}$
(c) HF only
(d) $\mathrm{H}_{2} \mathrm{~F}_{2}$ and $\mathrm{HFO}_{4}$.

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Problem 55

Which gas is produced when calcium nitride $\left(\mathrm{Ca}_{3} \mathrm{~N}_{2}\right)$ is hydrolysed by water?
(a) $\mathrm{N}_{2}$
(b) $\mathrm{NH}_{3}$
(c) $\mathrm{H}_{2}$
(d) $\mathrm{O}_{2}$

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Problem 56

Study the following reactions and mark the correct properties shown by water.
(i) $\mathrm{SO}_{3}+\mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{H}_{2} \mathrm{SO}_{4}$
(ii) $\mathrm{Cl}_{2} \mathrm{O}_{7}+\mathrm{H}_{2} \mathrm{O} \rightarrow 2 \mathrm{HClO}_{4}$
(iii) $\mathrm{CaO}+\mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{Ca}(\mathrm{OH})_{2}$
(iv) $\mathrm{Na}_{2} \mathrm{O}+\mathrm{H}_{2} \mathrm{O} \rightarrow 2 \mathrm{NaOH}$
(a) All oxides react with water to give hydroxides.
(b) Acidic oxides are formed by metals and basic oxides by non-metals.
(c) Non-metal oxides combine with water to form acids while metallic oxides combine with water to form alkalies.
(d) Acidic oxides are stronger than basic oxides since they form strong acids.

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Problem 57

How many hydrogen bonded water molecules are associated with $\mathrm{CuSO}_{4} \cdot 5 \mathrm{H}_{2} \mathrm{O}$ ?
(a) Five
(b) One
(c) Four
(d) Three

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Problem 58

During hydrate formation from aqueous solution, water can be associated in different forms. Indicate the wrong combination.
(i) Coordinated water - $\left[\mathrm{Cr}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{3+} 3 \mathrm{Cl}^{-}$
(ii) Interstitial water - $\mathrm{BaCl}_{2} \cdot 2 \mathrm{H}_{2} \mathrm{O}$
(iii) Hydrogen bonded water $\left[\mathrm{Cu}\left(\mathrm{H}_{2} \mathrm{O}\right)_{4}\right]^{2+} \mathrm{SO}_{4}^{2-} \cdot \mathrm{H}_{2} \mathrm{O}$
(a) (i)
(b) (ii)
(c) (iii)
(d) None of these.

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01:01

Problem 59

The temporary hardness of water due to calcium bicarbonate can be removed by adding
(a) $\mathrm{CaCO}_{3}$
(b) $\mathrm{CaCl}_{2}$
(c) $\mathrm{HCl}$
(d) $\mathrm{Ca}(\mathrm{OH})_{2}$

Narayan H.

Numerade Educator

01:01

Problem 60

The process used for the removal of hardness of water
is
(a) Baeyer
(b) Calgon
(c) Hoope
(d) Serpeck

Narayan H.

Numerade Educator

Problem 61

A water sample is said to contain permanent hardness if water contains
(a) sulphates and chlorides of calcium and magnesium
(b) carbonates of calcium and magnesium
(c) bicarbonates of calcium and magnesium
(d) sulphates and chlorides of sodium and potassium.

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Problem 62

In a permutit, the calcium and magnesium ions of hard water are exchanged by
(a) $\mathrm{CO}_{3}^{2-}$ and $\mathrm{HCO}_{3}^{-}$ions of permutit
(b) $\mathrm{Na}^{+}$ions of permutit
(c) $\mathrm{Al}^{3 *}$ ions of permutit
(d) $\mathrm{Si}^{4+}$ jons of permutit.

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Problem 63

Which of the following represents calgon?
(a) $\mathrm{Na}_{2} \mathrm{Al}_{2} \mathrm{Si}_{2} \mathrm{O}_{3}$
(b) $\mathrm{Mg}_{3}\left(\mathrm{PO}_{4}\right)_{2}$
(c) $\mathrm{Na}_{2}\left[\mathrm{Na}_{4}\left(\mathrm{PO}_{3}\right)_{6\}}\right.$
(d) $\mathrm{Na}_{2}\left[\mathrm{Mg}_{2}\left(\mathrm{PO}_{3}\right)_{6}\right]$

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Problem 64

Match the column I with column II and mark the appropriate choice.
(a) $(A) \rightarrow(i),(B) \rightarrow($ ii) $,(C) \rightarrow($ iii $),(D) \rightarrow$ (iv)
(b) $(A) \rightarrow($ iii $),(B) \rightarrow(i),(C) \rightarrow(i i),(D) \rightarrow$ (iv)
(c) $(A) \rightarrow$ (iii), (B) $\rightarrow$ (ii), $(C) \rightarrow$ (iv), (D) $\rightarrow$ (i)
(d) $(A) \rightarrow(\mathrm{iii}),(\mathrm{B}) \rightarrow(\mathrm{ii}),(\mathrm{C}) \rightarrow(\mathrm{i}),(\mathrm{D}) \rightarrow(\mathrm{iv})$

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Problem 65

The formula for permutit or zeolite which is used as softner in ion-exchange method is
(a) $\mathrm{NaAISiO}_{4}$
(b) $\mathrm{NaAlO}_{2}$
(c) $\mathrm{Ca}_{3}\left(\mathrm{PO}_{4}\right)_{2}$
(d) $\mathrm{Na}_{2} \mathrm{SO}_{4}$

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Problem 66

Match the column I with column II and mark the appropriate choice.
(a) $(A) \rightarrow(i),(B) \rightarrow($ iii), (C) $\rightarrow$ (iv), (D) $\rightarrow$ (ii)
(b) $(\mathrm{A}) \rightarrow(\mathrm{ii}),(\mathrm{B}) \rightarrow(\mathrm{iii}),(\mathrm{C}) \rightarrow(\mathrm{iv}),(\mathrm{D}) \rightarrow(\mathrm{i})$
(c) $(A) \rightarrow(i i i),(B) \rightarrow(i i),(C) \rightarrow(i),(D) \rightarrow(i v)$
(d) $(A) \rightarrow(i v),(B) \rightarrow(i),(C) \rightarrow(i i),(D) \rightarrow$ (iii)

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Problem 67

Presence of water can be detected by
(a) adding a drop to anhydrous copper sulphate which changes its colour from white to blue
(b) by boiling and testing for the presence of $\mathrm{H}_{2}$ and $\mathrm{O}_{2}$
(c) by seeing its colour and transparency
(d) by checking the production of lather when mixed with soap.

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Problem 68

Which of the following is not a disadvantage of using hard water?
(a) In production of steam in boilers
(b) Formation of scales in cooking utensils
(c) In cooking, bathing and washing
(d) In ion exchangers

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Problem 69

Polyphosphates like sodium hexametaphosphate (calgon) are used as water softening agents because they
(a) form soluble complexes with anionic species
(b) precipitate anionic species
(c) form soluble complexes with cationic species
(d) precipitate cationic species.

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Problem 70

What is meant by demineralised water?
(a) Water free from cations and anions.
(b) Water free from minerals dissolved in it.
(c) Water free from impurities.
(d) Water free from $\mathrm{Na}^{+}$and $\mathrm{K}^{+}$ions.

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Problem 71

Which of the following represents the chemical equation involved in the preparation of $\mathrm{H}_{2} \mathrm{O}_{2}$ from barium peroxide?
(a) $\mathrm{BaO}_{2} \cdot 8 \mathrm{H}_{2} \mathrm{O}+\mathrm{H}_{2} \mathrm{SO}_{4} \rightarrow \mathrm{BaSO}_{4}+\mathrm{H}_{2} \mathrm{O}_{2}+8 \mathrm{H}_{2} \mathrm{O}$
(b) $\mathrm{CH}_{3} \mathrm{CHOHCH}_{3}+\mathrm{O}_{2} \rightarrow \mathrm{CH}_{3} \mathrm{COCH}_{3}+\mathrm{H}_{2} \mathrm{O}_{2}$
(c) $\mathrm{BaO}_{2}+\mathrm{CO}_{2}+\mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{BaCO}_{3}+\mathrm{H}_{2} \mathrm{O}_{2}$
(d) $\mathrm{Ba}_{3}\left(\mathrm{PO}_{4}\right)_{2}+3 \mathrm{H}_{2} \mathrm{SO}_{4} \rightarrow 3 \mathrm{BaSO}_{4}+2 \mathrm{H}_{3} \mathrm{PO}_{4}$

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Problem 72

Which of the following is not a process of preparation of hydrogen peroxide?
(a) Auto-oxidation of 2 -ethylanthraquinol.
(b) By passing oxygen through boiling water.
(c) By oxidation of isopropyl alcohol.
(d) By reaction of barium peroxide with dil. $\mathrm{H}_{2} \mathrm{SO}_{4}$

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Problem 73

Which of the following reagents cannot be used for the preparation of hydrogen peroxide?
(a) Sodium peroxide
(b) 2 - Ethylanthraquinol
(c) Sodium thiosulphate
(d) Barium peroxide

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Problem 74

Peroxodisulphate, on hydrolysis yields
(a) water
(b) dihydrogen
(c) hydrogen peroxide
(d) deuterium.

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Problem 75

A commercial sample of hydrogen peroxide is labelled as 10 volume. Its percentage strength is nearly
(a) $3 \%$
(b) $1 \%$
(c) $90 \%$
(d) $10 \%$

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Problem 76

Strength of 10 volume hydrogen peroxide solution means
(a) $30.35 \mathrm{~g} \mathrm{~L}^{-1}$
(b) $17 \mathrm{~g} \mathrm{~L}^{-1}$
(c) $34 \mathrm{~g} \mathrm{~L}^{-1}$
(d) $68 \mathrm{~g} \mathrm{~L}^{-1}$

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Problem 77

What will be the strength of 20 vol of $\mathrm{H}_{2} \mathrm{O}_{2}$ in terms of gram per litre?
(a) $60.71 g \mathrm{~L}$
(b) $5.6 \mathrm{~g} \mathrm{~L}^{-1}$
(c) $30.62 \mathrm{~g}^{-1}$
(d) $17 \mathrm{~g} \mathrm{~L}^{-1}$

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Problem 78

What will be the $200 \mathrm{~mL}$ hydrogen peroxide solution 2. decouposition of 34 g per litre?
(b) $3.0 \mathrm{~g}$
$\begin{array}{ll}\text { 2. } 25.5 \mathrm{~g} & \text { (d) } 4.2 \mathrm{~g}\end{array}$
(a) $3.2 \mathrm{~g}$

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Problem 79

Which of the following is a true structure of $\mathrm{H}_{2} \mathrm{O}_{2}$ which
in solid phase?

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Problem 80

Two structures of $\mathrm{H}_{2} \mathrm{O}_{2}$ are drawn below. Identify the phases $X$ and $Y$ of $\mathrm{H}_{2} \mathrm{O}_{2}$.

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Problem 81

Mark the following statements as true or false.
(i) Ordinary hydrogen is a mixture of $75 \%$ ortho and $25 \%$ para-forms.
(ii) All the four atoms of molecule of $\mathrm{H}_{2} \mathrm{O}_{2}$ lie in the same plane.
(iii) Hydrogen peroxide is neutral like water.
(iv) $\mathrm{H}_{2} \mathrm{O}_{2}$ can be prepared from $\mathrm{BaO}_{2}$ but not from $\mathrm{MnO}_{2}$ and $\mathrm{PbO}_{2}$
(a) (i) and (iv) - true, (ii) and (iii) - false
(b) (i) and (ii) - true, (iii) and (iv) - false
(c) (iii) and (iv) - true, (i) and (ii) - false
(d) (i) and (iii) - true, (ii) and (iv) - false

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Problem 82

Which of the following statements regarding hydrogen peroxide is false?
(a) It is a strong oxidising agent.
(b) It is decomposed by $\mathrm{MnO}_{2}$.
(c) It behaves as a reducing agent.
(d) It is more stable in basic solution.

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Problem 83

$\mathrm{H}_{2} \mathrm{O}_{2}$ acts as a bleaching agent because of
(a) reducing nature of $\mathrm{H}_{2} \mathrm{O}_{2}$
(b) oxidising nature of $\mathrm{H}_{2} \mathrm{O}_{2}$
(c) acidic nature of $\mathrm{H}_{2} \mathrm{O}_{2}$
(d) basic nature of $\mathrm{H}_{2} \mathrm{O}_{2}$.

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Problem 84

Given below are the two reactions of $\mathrm{H}_{2} \mathrm{O}_{2}$. Mark the correct statement which follows.
(i) $2 \mathrm{KMnO}_{4}+3 \mathrm{H}_{2} \mathrm{SO}_{4}+5 \mathrm{H}_{2} \mathrm{O}_{2} \rightarrow \mathrm{K}_{2} \mathrm{SO}_{4}+2 \mathrm{MnSO}_{4}$
$+8 \mathrm{H}_{2} \mathrm{O}+5 \mathrm{O}_{2}$
(ii) $2 \mathrm{Cr}(\mathrm{OH})_{3}+4 \mathrm{NaOH}+3 \mathrm{H}_{2} \mathrm{O}_{2} \rightarrow 2 \mathrm{Na}_{2} \mathrm{CrO}_{4}+$
(a) (i) Shows oxidising nature of $\mathrm{H}_{2} \mathrm{O}_{2}$ and (ii) shows reducing nature of $\mathrm{H}_{2} \mathrm{O}_{2}$
(b) In (i) $\mathrm{H}_{2} \mathrm{O}_{2}$ acts as a reducing agent and in (ii) it acts as an oxidising agent.
(c) In both (i) and (ii), $\mathrm{H}_{2} \mathrm{O}_{2}$ acts as an oxidising agent.
(d) In both (i) and (ii), $\mathrm{H}_{2} \mathrm{O}_{2}$ acts as a reducing agent.

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Problem 85

What happens when an alkaline solution of potassium ferricyanide is reacted with $\mathrm{H}_{2} \mathrm{O}_{2} ?$
(a) Potassium ferricyanide is oxidised to potassium ferrocyanide and $\mathrm{H}_{2} \mathrm{O}_{2}$ is oxidised.
(b) Potassium ferricyanide becomes colourless and $\mathrm{H}_{2} \mathrm{O}_{2}$ is oxidised to $\mathrm{O}_{2}$.
(c) Potassium ferricyanide is reduced to ferric hydroxide and $\mathrm{H}_{2} \mathrm{O}_{2}$ is oxidised to $\mathrm{H}_{2} \mathrm{O}$
(d) Potassium ferricyanide is reduced to potassium ferrocyanide and $\mathrm{H}_{2} \mathrm{O}_{2}$ is oxidised to $\mathrm{O}_{2}$.

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Problem 86

When $\mathrm{CO}_{2}$ is bubbled through a solution of barium peroxide in water
(a) carbonic acid is formed
(b) $\mathrm{H}_{2} \mathrm{O}_{2}$ is formed
(c) $\mathrm{H}_{2} \mathrm{O}$ is formed
(d) barium hydroxide is formed.

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Problem 87

Which of the following reactions shows reducing nature of $\mathrm{H}_{2} \mathrm{O}_{2}$ ?
(a) $\mathrm{PbS}+4 \mathrm{H}_{2} \mathrm{O}_{2} \rightarrow \mathrm{PbSO}_{4}+4 \mathrm{H}_{2} \mathrm{O}$
(b) $\mathrm{Ag}_{2} \mathrm{O}+\mathrm{H}_{2} \mathrm{O}_{2} \rightarrow 2 \mathrm{Ag}+\mathrm{H}_{2} \mathrm{O}+\mathrm{O}_{2}$
(c) $2 \mathrm{HCHO}+\mathrm{H}_{2} \mathrm{O}_{2} \rightarrow 2 \mathrm{HCOOH}+\mathrm{H}_{2} \mathrm{O}$
(d) $\mathrm{Na}_{2} \mathrm{SO}_{3}+\mathrm{H}_{2} \mathrm{O}_{2} \rightarrow \mathrm{Na}_{2} \mathrm{SO}_{4}+\mathrm{H}_{2} \mathrm{O}$

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Problem 88

Which of the following act as a stabiliser for the storage of $\mathrm{H}_{2} \mathrm{O}_{2} ?$
(a) Alkali
(b) Dust
(c) Urea
(d) None of these.

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Problem 89

Statues and paintings coated with white lead turn black on long exposure to atmosphere. The original colour can be restored by treating them with $\mathrm{H}_{2} \mathrm{O}_{2}$ The reason behind this is
(a) blackened statues get coated with PbS which on reaction with $\mathrm{H}_{2} \mathrm{O}_{2}$ is oxidised to white $\mathrm{PbSO}_{4}$
(b) $\mathrm{H}_{2} \mathrm{O}_{2}$ dissolves the coating of white lead and exposes the inner surface.
(c) white lead reacts with $\mathrm{H}_{2} \mathrm{O}_{2}$ to form white $\mathrm{PbSO}_{4}$
(d) blackened statues get coated with lead sulphate which reacts with $\mathrm{H}_{2} \mathrm{O}_{2}$ to give $\mathrm{PbS}$.

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Problem 90

Which of the following easily catalyse the decomposition of $\mathrm{H}_{2} \mathrm{O}_{2}$ when stored?
(i) Rough surface
(ii) Sunlight
(iii) Dust particles
(iv) Metals
(a) (i) and (ii)
(b) (i), (ii) and (iii)
(c) (ii) and (iii)
(d) All of these.

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Problem 91

Last traces of water is removed from $\mathrm{H}_{2} \mathrm{O}_{2}$ by
(a) electrolysis
(b) crystallisation
(c) condensation
(d) evaporation.

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Problem 92

Which of the following cannot be used as a test for $\mathrm{H}_{2} \mathrm{O}_{2} ?$
(a) A paper dipped in PbS (black) turns white when brought in contact with $\mathrm{H}_{2} \mathrm{O}_{2}$.
(b) It liberates iodine from KI solution which gives blue colour with starch solution.
(c) It gives blue colour with $\mathrm{K}_{4}\left[\mathrm{Fe}(\mathrm{CN})_{6}\right]$.
(d) It decolourises acidified $\mathrm{KMnO}_{4}$ solution.

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Problem 93

What is heavy water?
(a) $\mathrm{H}_{2} \mathrm{O}^{18}$
(b) $\mathrm{D}_{2} \mathrm{O}$
(c) $\mathrm{H}_{2} \mathrm{O}^{17}$
(d) $\mathrm{H}_{2} \mathrm{O}$

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Problem 94

Heavy water is obtained by
(a) boiling water
(b) heating $\mathrm{H}_{2} \mathrm{O}_{2}$
(c) prolonged electrolysis of $\mathrm{H}_{2} \mathrm{O}$
(d) All of these.

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Problem 95

Which of the following reactions is not used in preparation of deuterium compounds using heavy water?
(a) $\mathrm{CaC}_{2}+2 \mathrm{D}_{2} \mathrm{O} \rightarrow \mathrm{C}_{2} \mathrm{D}_{2}+\mathrm{Ca}(\mathrm{OD})_{2}$
(b) $\mathrm{SO}_{3}+\mathrm{D}_{2} \mathrm{O} \rightarrow \mathrm{D}_{2} \mathrm{SO}_{4}$
(c) $2 \mathrm{AlN}+3 \mathrm{D}_{2} \mathrm{O} \rightarrow \mathrm{Al}_{2} \mathrm{O}_{3}+2 \mathrm{ND}$
(d) $\mathrm{Al}_{4} \mathrm{C}_{3}+12 \mathrm{D}_{2} \mathrm{O} \rightarrow 3 \mathrm{CD}_{4}+4 \mathrm{Al}(\mathrm{OD})_{3}$

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Problem 96

The boiling point of heavy water is
(a) $100^{\circ} \mathrm{C}$
(b) $101.4{ }^{\circ} \mathrm{C}$
(c) $99^{\circ} \mathrm{C}$
(d) $110^{\circ} \mathrm{C}$

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Problem 97

Heavy water $\left(\mathrm{D}_{2} \mathrm{O}\right)$ freezes at
(a) $-3.8^{\circ} \mathrm{C}$
(b) $3.8^{\circ} \mathrm{C}$
(c) $0^{\circ} \mathrm{C}$
(d) $38^{\circ} \mathrm{C}$

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Problem 98

Which compound is formed when calcium carbide reacts with heavy water?
(a) $\mathrm{C}_{2} \mathrm{D}_{2}$
(b) $\mathrm{CaD}_{2}$
(c) $\mathrm{CD}_{2}$
(d) $\mathrm{Ca}_{2} \mathrm{D}_{2}$

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Problem 99

Heavy water is used as
(a) drinking water
(b) detergent
(c) washing water
(d) a moderator.

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Problem 100

Some of the major uses of heavy water are given below. Which one is not correct?
(a) It is used as a moderator in nuclear reactors.
(b) It is used as a tracer compound for studying reaction mechanism.
(c) High concentration of heavy water accelerates the growth of plants.
(d) It is used in preparing deuterium.

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