Introductory Chemistry Essentials

Tro, Nivaldo J.

Chapter 15

Chemical Equilibrium - all with Video Answers

Educators

Chapter Questions

Problem 1

Is life in equilibrium with the environment? Give one example to support your answer.

John Nicolle

John Nicolle

Numerade Educator

Problem 2

What is the rate of a chemical reaction? What is the difference between a chemical reaction with a fast rate and one with a slow rate?

Lottie Adams

Numerade Educator

Problem 3

Why do chemists seek to control reaction rates?

Lottie Adams

Numerade Educator

Problem 4

How do most chemical reactions occur?

Lottie Adams

Numerade Educator

Problem 5

What factors influence reaction rates? How?

Lottie Adams

Numerade Educator

Problem 6

What normally happens to the rate of the forward reaction as a reaction proceeds?

Lottie Adams

Numerade Educator

Problem 7

What is dynamic chemical equilibrium?

Lottie Adams

Numerade Educator

Problem 8

Explain how dynamic chemical equilibrium involves the concepts of sameness and constancy.

Lottie Adams

Numerade Educator

Problem 9

Explain why the concentrations of reactants and products are not necessarily the same at equilibrium.

Lottie Adams

Numerade Educator

Problem 10

Use the Narnia and Middle Earth analogy to describe the difference between static and dynamic equilibrium.

Lottie Adams

Numerade Educator

Problem 11

What is the equilibrium constant? Why is it significant?

Lottie Adams

Numerade Educator

Problem 12

Write the expression for the equilibrium constant for the following generic chemical equation.
$$
a \mathrm{~A}+b \mathrm{~B} \rightleftharpoons c \mathrm{C}+d \mathrm{D}
$$

Lottie Adams

Numerade Educator

Problem 13

What does a small equilibrium constant tell you about a reaction? A large equilibrium constant?

Lottie Adams

Numerade Educator

Problem 14

Why are solids and liquids omitted from the equilibrium expression?

Lottie Adams

Numerade Educator

Problem 15

Will the concentrations of reactants and products always be the same in every equilibrium mixture of a particular reaction at a given temperature? Explain.

Lottie Adams

Numerade Educator

Problem 16

According to Le Châtelier's principle, how will a system at equilibrium respond to disturbance?

Lottie Adams

Numerade Educator

Problem 17

Apply Le Châtelier's principle to your analogy from Question $12 .$

Lottie Adams

Numerade Educator

Problem 18

What is the effect of increasing the concentration of a reactant in a reaction mixture at equilibrium?

Lottie Adams

Numerade Educator

Problem 19

What is the effect of decreasing the concentration of a reactant in a reaction mixture at equilibrium?

Lottie Adams

Numerade Educator

Problem 20

What is the effect of increasing the concentration of a product in a reaction mixture at equilibrium?

Lottie Adams

Numerade Educator

Problem 21

What is the effect of decreasing the concentration of a product in a reaction mixture at equilibrium?

Lottie Adams

Numerade Educator

Problem 22

What is the effect of increasing the volume of the reaction vessel on a reaction mixture at equilibrium if the reactant side has more moles of gas particles than the product side?

Lottie Adams

Numerade Educator

Problem 23

What is the effect of increasing the pressure of a reaction mixture at equilibrium if the product side has fewer moles of gas particles than the reactant side?

Lottie Adams

Numerade Educator

Problem 24

To drive a reaction that has fewer moles of gas particles on the reactant side than the product side, would you increase or decrease the volume of the reaction vessel?

Lottie Adams

Numerade Educator

Problem 25

What is the effect of decreasing the pressure of a reaction mixture at equilibrium if the product side has fewer moles of gas particles than the reactant side?

Lottie Adams

Numerade Educator

Problem 26

What is the effect of increasing the temperature of an exothermic reaction mixture at equilibrium? Of decreasing the temperature?

Lottie Adams

Numerade Educator

Problem 27

To drive an endothermic reaction at equilibrium to the product side, would you increase or decrease the temperature of the reaction mixture?

Karoline García

Karoline García

Numerade Educator

Problem 28

What is the solubility-product constant? What does it signify?

Lottie Adams

Numerade Educator

Problem 29

Write an expression for the solubility-product constant of $A B_{2}(s) .$ Assume that an ion of $B$ has a charge of $1-$ (that is, $\left.B^{-}\right)$

Lottie Adams

Numerade Educator

Problem 30

Write an expression each for the solubility-product constants of $\mathrm{LiCl}, \mathrm{K}_{2} \mathrm{SO}_{4}$ and $\mathrm{Mg}_{3}\left(\mathrm{PO}_{4}\right)_{2}$

Sima Sarker

Numerade Educator

Problem 31

What are solubility and molar solubility?

Shalini Tyagi

Numerade Educator

Problem 32

What is activation energy for a chemical reaction?

Lottie Adams

Numerade Educator

Problem 33

Despite the fact that the reaction between hydrogen and oxygen to form water has a very large $K_{e q}$ of $3.2 \times 10^{81}$ at $25^{\circ} \mathrm{C},$ no reaction would be observed by mixing hydrogen and oxygen at room temperature. Why?

Stephen Ho

Numerade Educator

Problem 34

What is a catalyst? What effect does increasing the concentration of the catalyst have on a reaction at equilibrium?

Ronald Prasad

Numerade Educator

Problem 35

Does a catalyst affect the value of the equilibrium constant?

Lottie Adams

Numerade Educator

Problem 36

What are enzymes?

Lottie Adams

Numerade Educator

Problem 37

Two gaseous reactants are allowed to react in a 1-L flask, and the reaction rate is measured. The experiment is repeated with the same amount of each reactant and at the same temperature in a 2 -L flask (so the concentration of each reactant is less). What is likely to happen to the measured reaction rate in the second experiment compared to the first?

Lottie Adams

Numerade Educator

Problem 38

The rate of phosphorus pentachloride decomposition is measured at a $\mathrm{PCl}_{5}$ pressure of $0.015 \mathrm{~atm}$ and then again at a $\mathrm{PCl}_{5}$ pressure of $0.30 \mathrm{~atm}$. The temperature is identical in both measurements. Which rate is likely to be faster?

Lottie Adams

Numerade Educator

Problem 39

The body temperature of cold-blooded animals varies with the ambient temperature. From the point of view of reaction rates, explain why cold-blooded animals are more sluggish at cold temperatures.

Lottie Adams

Numerade Educator

Problem 40

How would the initial rate of a chemical reaction change with increasing temperature?

Karoline García

Karoline García

Numerade Educator

Problem 41

The initial rate of a chemical reaction was measured, and one of the reactants was found to be reacting at a rate of $0.0011 \mathrm{~mol} / \mathrm{L}$ s. The reaction was allowed to proceed for 15 minutes, and the rate was measured again. What would you predict about the second measured rate relative to the first?

Lottie Adams

Numerade Educator

Problem 42

When vinegar is added to a solution of sodium bicarbonate, the mixture immediately begins to bubble furiously. As time passes, however, there is less and less bubbling. Explain why this happens.

Lottie Adams

Numerade Educator

Problem 43

Write an equilibrium expression for each chemical equation.
(a) $2 \mathrm{NO}_{2}(g) \rightleftharpoons \mathrm{N}_{2} \mathrm{O}_{4}(g)$
(b) $2 \mathrm{BrNO}(g) \rightleftharpoons 2 \mathrm{NO}(g)+\mathrm{Br}_{2}(g)$
(c) $\mathrm{H}_{2} \mathrm{O}(g)+\mathrm{CO}(g) \rightleftharpoons \mathrm{H}_{2}(g)+\mathrm{CO}_{2}(g)$
(d) $\mathrm{CH}_{4}(g)+2 \mathrm{H}_{2} \mathrm{~S}(g) \rightleftharpoons \mathrm{CS}_{2}(g)+4 \mathrm{H}_{2}(g)$

Lottie Adams

Numerade Educator

Problem 44

Write an equilibrium expression for each chemical equation.
(a) $3 \mathrm{H}_{2}(g)+\mathrm{N}_{2}(g) \rightleftharpoons 2 \mathrm{NH}_{3}(g)$
(b) $\mathrm{CO}_{3}^{2-}(a q)+\mathrm{HSO}_{4}^{-}(a q) \rightleftharpoons \mathrm{SO}_{4}^{2-}(a q)+\mathrm{HCO}_{3}^{-}(a q)$
(c) $\mathrm{Al}(\mathrm{OH})_{3}(a q)+\mathrm{OH}(a q) \rightleftharpoons \mathrm{Al}(\mathrm{OH})_{4}^{-}(a q)$
(d) $2 \mathrm{~N}_{2} \mathrm{O}_{5}(g) \rightleftharpoons 4 \mathrm{NO}_{2}(g)+\mathrm{O}_{2}(g)$

Lottie Adams

Numerade Educator

Problem 45

Write an equilibrium expression for each chemical equation involving one or more solid or liquid reactants or products.
(a) $\mathrm{PCl}_{5}(g) \rightleftharpoons \mathrm{PCl}_{3}(l)+\mathrm{Cl}_{2}(g)$
(b) $2 \mathrm{KClO}_{3}(s) \rightleftharpoons 2 \mathrm{KCl}(s)+3 \mathrm{O}_{2}(g)$
(c) $\mathrm{HF}(a q)+\mathrm{H}_{2} \mathrm{O}(l) \rightleftharpoons \mathrm{H}_{3} \mathrm{O}^{+}(a q)+\mathrm{F}^{-}(a q)$
(d) $\mathrm{NH}_{3}(a q)+\mathrm{H}_{2} \mathrm{O}(l) \rightleftharpoons \mathrm{NH}_{4}{ }^{+}(a q)+\mathrm{OH}^{-}(a q)$

Lottie Adams

Numerade Educator

Problem 46

Write an equilibrium expression for each chemical equation involving one or more solid or liquid reactants or products.
(a) $\mathrm{HCHO}_{2}(a q)+\mathrm{H}_{2} \mathrm{O}(l) \rightleftharpoons \mathrm{H}_{3} \mathrm{O}^{+}(a q)+\mathrm{CHO}_{2}^{-}(a q)$
(b) $\mathrm{CO}_{3}^{2-}(a q)+\mathrm{H}_{2} \mathrm{O}(l) \rightleftharpoons \mathrm{HCO}_{3}^{-}(a q)+\mathrm{OH}^{-}(a q)$
(c) $2 \mathrm{C}(s)+\mathrm{O}_{2}(g) \rightleftharpoons 2 \mathrm{CO}(g)$
(d) $\mathrm{C}(s)+\mathrm{CO}_{2}(g) \rightleftharpoons 2 \mathrm{CO}(g)$

Lottie Adams

Numerade Educator

Problem 47

Consider the reaction.
$$
2 \mathrm{H}_{2} \mathrm{~S}(g) \rightleftharpoons 2 \mathrm{H}_{2}(g)+\mathrm{S}_{2}(g)
$$
Find the mistakes in the equilibrium expression and fix them.
$$
K_{\mathrm{eq}}=\frac{\left[\mathrm{H}_{2}\right]\left[\mathrm{S}_{2}\right]}{\left[\mathrm{H}_{2} \mathrm{~S}\right]}
$$

Lottie Adams

Numerade Educator

Problem 48

Consider the reaction.
$$
\mathrm{Fe}^{3+}(a q)+\mathrm{SCN}^{-}(a q) \rightleftharpoons[\mathrm{Fe}(\mathrm{SCN})]^{2+}(a q)
$$
Find the mistake in the equilibrium expression and fix it.
$$
K_{\mathrm{eq}}=\frac{\left[\mathrm{Fe}^{3+}\right]^{3}\left[\mathrm{SCN}^{-}\right]}{\left[[\mathrm{Fe}(\mathrm{SCN})]^{2+}\right]^{2}}
$$

David Collins

Numerade Educator

Problem 49

For each equilibrium constant, indicate if you would expect an equilibrium reaction mixture to be dominated by reactants or by products, or to contain significant amounts of both.
(a) $K_{\text {eq }}=5.2 \times 10^{17}$
(b) $K_{\mathrm{eq}}=1.24$
(c) $K_{\text {eq }}=3.22 \times 10^{-21}$
(d) $K_{\mathrm{eq}}=0.47$

Lottie Adams

Numerade Educator

Problem 50

For the reaction with reactant $A,$ and product $B,$ estimate $\mathrm{K}_{\mathrm{eq}}$ if the equilibrium mixture has the following ratios of A and B.
(a) $\mathrm{A}: \mathrm{B}=2: 9$
(b) $\mathrm{A}: \mathrm{B}=0.5: 5 \times 10^{6}$
(c) $\mathrm{A}: \mathrm{B}=3 \times 10^{8}: 4 \times 10^{-3}$
(d) $A: B=4: 1$

Matthew Hurlock

Matthew Hurlock

Numerade Educator

Problem 51

Consider the reaction.
$$
\mathrm{COCl}_{2}(g) \rightleftharpoons \mathrm{CO}(g)+\mathrm{Cl}_{2}(g)
$$
An equilibrium mixture of this reaction at a certain temperature has $\left[\mathrm{COCl}_{2}\right]=0.225 \mathrm{M},[\mathrm{CO}]=0.105 \mathrm{M},$ and
$\left[\mathrm{Cl}_{2}\right]=0.0844 \mathrm{M}$. What is the value of the equilibrium constant at this temperature?

Andrew Eddins

Emory University

Problem 52

Consider the reaction.
$$
\mathrm{CO}(g)+2 \mathrm{H}_{2}(g) \rightleftharpoons \mathrm{CH}_{3} \mathrm{OH}(g)
$$
An equilibrium mixture of this reaction at a certain temperature has $[\mathrm{CO}]=0.105 \mathrm{M},\left[\mathrm{H}_{2}\right]=0.114 \mathrm{M},$ and
$\left[\mathrm{CH}_{3} \mathrm{OH}\right]=0.185 \mathrm{M} .$ What is the value of the equilibrium constant at this temperature?

Lottie Adams

Numerade Educator

Problem 53

Consider the reaction.
$$
2 \mathrm{SO}_{2}(g)+\mathrm{O}_{2}(g) \rightleftharpoons 2 \mathrm{SO}_{3}(g)
$$
At equilibrium, the concentrations of $\mathrm{SO}_{2}, \mathrm{O}_{2}$ and $\mathrm{SO}_{3}$ were found to be $0.53 \mathrm{M}, 0.10 \mathrm{M},$ and $2.8 \mathrm{M},$ respectively, at a given temperature. What is the value of the equilibrium constant at this temperature?

Kevin Zaborsky

Numerade Educator

Problem 54

Consider the reaction.
$$
\mathrm{CO}(g)+\mathrm{H}_{2} \mathrm{O}(g) \rightleftharpoons \mathrm{CO}_{2}(g)+\mathrm{H}_{2}(g)
$$
An equilibrium mixture of this reaction at a certain temperature has $[\mathrm{CO}]=0.0233 \mathrm{M},\left[\mathrm{H}_{2} \mathrm{O}\right]=0.0115 \mathrm{M}$
$\left[\mathrm{CO}_{2}\right]=0.175 \mathrm{M},$ and $\left[\mathrm{H}_{2}\right]=0.0274 \mathrm{M} .$ What is the value
of the equilibrium constant at this temperature?

Lottie Adams

Numerade Educator

Problem 55

Consider the reaction.
$$
\mathrm{NH}_{4} \mathrm{HS}(s) \rightleftharpoons \mathrm{NH}_{3}(g)+\mathrm{H}_{2} \mathrm{~S}(g)
$$
An equilibrium mixture of this reaction at a certain temperature has $\left[\mathrm{NH}_{3}\right]=0.278 \mathrm{M}$ and $\left[\mathrm{H}_{2} \mathrm{~S}\right]=0.355 \mathrm{M}$
What is the value of the equilibrium constant at this temperature?

Lottie Adams

Numerade Educator

Problem 56

Consider the reaction.
$$
4 \mathrm{KO}_{2}(s)+2 \mathrm{CO}_{2}(g) \rightleftharpoons 2 \mathrm{~K}_{2} \mathrm{CO}_{3}(\mathrm{~s})+3 \mathrm{O}_{2}(g)
$$
At equilibrium, the concentration of $\mathrm{CO}_{2}$, and $\mathrm{O}_{2}$ were found to be $0.23 \mathrm{M}$ and $0.86 \mathrm{M}$, respectively, at a certain temperature. What is the value of the equilibrium constant at this temperature?

Andrew Eddins

Emory University

Problem 57

An equilibrium mixture of the following reaction is found to have $\left[\mathrm{SbCl}_{3}\right]=0.0255 \mathrm{M}$ and $\left[\mathrm{Cl}_{2}\right]=0.135 \mathrm{M}$ at $248{ }^{\circ} \mathrm{C}$.
What is the concentration of $\mathrm{SbCl}_{5} ?$
$$
\begin{array}{c}
\mathrm{SbCl}_{5}(g) \rightleftharpoons \mathrm{SbCl}_{3}(g)+\mathrm{Cl}_{2}(g) \\
K_{\mathrm{eq}}=4.9 \times 10^{-4} \text {at } 248^{\circ} \mathrm{C}
\end{array}
$$

Lottie Adams

Numerade Educator

Problem 58

An equilibrium mixture of the following reaction has $\left[\mathrm{I}_{2}\right]=0.0205 \mathrm{M}$ at $1200{ }^{\circ} \mathrm{C}$. What is the concentration of $\mathrm{I} ?$
$$
\begin{array}{c}
\mathrm{I}_{2}(g) \rightleftharpoons 2 \mathrm{I}(g) \\
K_{\mathrm{eq}}=1.1 \times 10^{-2} \text {at } 1200{ }^{\circ} \mathrm{C}
\end{array}
$$

Lottie Adams

Numerade Educator

Problem 59

An equilibrium mixture of the following reaction has $\left[\mathrm{I}_{2}\right]=0.0112 \mathrm{M}$ and $\left[\mathrm{Cl}_{2}\right]=0.0155 \mathrm{M}$ at $25^{\circ} \mathrm{C} .$ What is the
concentration of ICl?
$$
\begin{array}{c}
\mathrm{I}_{2}(g)+\mathrm{Cl}_{2}(g) \rightleftharpoons 2 \mathrm{ICl}(g) \\
K_{\mathrm{eq}}=81.9 \text { at } 25^{\circ} \mathrm{C}
\end{array}
$$

Lottie Adams

Numerade Educator

Problem 60

Dissolving certain amount of $\left[\mathrm{Al}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{3+}$ in water at room temperature will give an equilibrium mixture having a pH value of $3.8 .$ Calculate the equilibrium concentration of $\left[\mathrm{Al}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{3+}$ at this temperature.
$$
\begin{array}{c}
{\left[\mathrm{Al}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{3+}(a q)+\mathrm{H}_{2} \mathrm{O}(l) \rightleftharpoons\left[\mathrm{Al}(\mathrm{OH})\left(\mathrm{H}_{2} \mathrm{O}\right)_{5}\right]^{2+}(a q)+\mathrm{H}_{3} \mathrm{O}^{+}(a q)} \\
K_{\mathrm{eq}}=1.4 \times 10^{-5} \text {at } 25^{\circ} \mathrm{C}
\end{array}
$$

Adriano Chikande

Adriano Chikande

Numerade Educator

Problem 61

Consider the reaction.
$$
\mathrm{N}_{2}(g)+3 \mathrm{H}_{2}(g) \rightleftharpoons 2 \mathrm{NH}_{3}(g)
$$
Complete the table. Assume that all concentrations are equilibrium concentrations in moles per liter, M.

Amy Jiang

Numerade Educator

Problem 62

Consider the reaction.
$$
\mathrm{H}_{2}(g)+\mathrm{I}_{2}(g) \rightleftharpoons 2 \mathrm{HI}(g)
$$
Complete the table. Assume that all concentrations are equilibrium concentrations in moles per liter, M.

Bailey Mccarthy Riley

Bailey Mccarthy Riley

Numerade Educator

Problem 63

Consider this reaction at equilibrium.
$$
\mathrm{CO}(g)+\mathrm{Cl}_{2}(g) \rightleftharpoons \mathrm{COCl}_{2}(g)
$$
Predict the effect (shift right, shift left, or no effect) of these changes.
(a) adding $\mathrm{Cl}_{2}$ to the reaction mixture
(b) adding $\mathrm{COCl}_{2}$ to the reaction mixture
(c) adding CO to the reaction mixture

Lottie Adams

Numerade Educator

Problem 64

Consider this reaction at equilibrium.
$$
2 \mathrm{BrNO}(g) \rightleftharpoons 2 \mathrm{NO}(g)+\mathrm{Br}_{2}(g)
$$
Predict the effect (shift right, shift left, or no effect) of these changes.
(a) adding BrNO to the reaction mixture
(b) adding NO to the reaction mixture
(c) adding $\mathrm{Br}_{2}$ to the reaction mixture

Lottie Adams

Numerade Educator

Problem 65

Consider this reaction at equilibrium.
$$
\mathrm{C}(s)+\mathrm{H}_{2} \mathrm{O}(g) \rightleftharpoons \mathrm{CO}(g)+\mathrm{H}_{2}(g)
$$
Predict the effect (shift right, shift left, or no effect) of these changes.
(a) adding $C$ to the reaction mixture
(b) condensing $\mathrm{H}_{2} \mathrm{O}$ and removing it from the reaction mixture
(c) adding CO to the reaction mixture
(d) removing $\mathrm{H}_{2}$ from the reaction mixture

Lottie Adams

Numerade Educator

Problem 66

Consider this reaction at equilibrium.
$$
\begin{array}{l}
2 \mathrm{HXeO}_{4}^{-}(a q)+2 \mathrm{OH}^{-}(a q) \rightleftharpoons \\
\mathrm{XeO}_{6}^{4-}(a q)+\mathrm{Xe}(g)+\mathrm{O}_{2}(g)+2 \mathrm{H}_{2} \mathrm{O}(l)
\end{array}
$$
Predict the effect (shift right, shift left, or no effect) of these changes.
(a) adding $\mathrm{NaOH}$ to the reaction mixture
(b) adding $\mathrm{HCl}$ to the reaction mixture
(c) adding Xe to the reaction mixture
(d) removing Xe from the reaction mixture

ES

Eugene Schneider

University of Minnesota - Twin Cities

Problem 67

Consider the effect of a volume change on this reaction at equilibrium.
$$
\operatorname{PBr}_{5}(g) \rightleftharpoons \operatorname{Br}_{2}(g)+\operatorname{PBr}_{3}(g)
$$
Predict the effect (shift right, shift left, or no effect) of these changes.
(a) increasing the reaction volume
(b) decreasing the reaction volume

Lottie Adams

Numerade Educator

Problem 68

Consider the effect of a volume change on this reaction at equilibrium.
$$
\mathrm{P}_{4}(s)+3 \mathrm{O}_{2}(g) \rightleftharpoons \mathrm{P}_{4} \mathrm{O}_{6}(l)
$$
Predict the effect (shift right, shift left, or no effect) of these changes.
(a) increasing the reaction volume
(b) decreasing the reaction volume

Lottie Adams

Numerade Educator

Problem 69

Consider the effect of a volume change on this reaction at equilibrium.
$$
\mathrm{I}_{2}(g)+\mathrm{Cl}_{2}(g) \rightleftharpoons 2 \mathrm{ICl}(g)
$$
Predict the effect (shift right, shift left, or no effect) of these changes.
(a) increasing the reaction volume
(b) decreasing the reaction volume

Lottie Adams

Numerade Educator

Problem 70

Consider the effect of a volume change on this reaction at equilibrium.
$$
\mathrm{CO}(g)+\mathrm{H}_{2} \mathrm{O}(g) \rightleftharpoons \mathrm{CO}_{2}(g)+\mathrm{H}_{2}(g)
$$
Predict the effect (shift right, shift left, or no effect) of these changes.
(a) increasing the reaction volume
(b) decreasing the reaction volume

Lottie Adams

Numerade Educator

Problem 71

This reaction is endothermic.
$$
\mathrm{C}(s)+\mathrm{CO}_{2}(g) \rightleftharpoons 2 \mathrm{CO}(g)
$$
Predict the effect (shift right, shift left, or no effect) of these changes.
(a) increasing the reaction temperature
(b) decreasing the reaction temperature

Lottie Adams

Numerade Educator

Problem 72

This reaction is endothermic.
$$
\mathrm{NH}_{4} \mathrm{Cl}(s)+\mathrm{H}_{2} \mathrm{O}(l) \rightleftharpoons \mathrm{NH}_{4}{ }^{+}(a q)+\mathrm{Cl}^{-}(a q)
$$
Predict the effect (shift right, shift left, or no effect) of these changes.
(a) increasing the reaction temperature
(b) decreasing the reaction temperature

Karoline García

Karoline García

Numerade Educator

Problem 73

This reaction is exothermic.
$$
\mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6}(s)+6 \mathrm{O}_{2}(g) \rightleftharpoons 6 \mathrm{CO}_{2}(g)+6 \mathrm{H}_{2} \mathrm{O}(g)
$$
Predict the effect (shift right, shift left, or no effect) of these changes.
(a) increasing the reaction temperature
(b) decreasing the reaction temperature

Lottie Adams

Numerade Educator

Problem 74

The following reaction is exothermic.
$$
\mathrm{C}_{2} \mathrm{H}_{4}(g)+\mathrm{Br}_{2}(g) \rightleftharpoons \mathrm{C}_{2} \mathrm{H}_{4} \mathrm{Br}_{2}(g)
$$
Predict the effect (shift right, shift left, or no effect) of these changes.
(a) increasing the reaction temperature
(b) decreasing the reaction temperature

Lottie Adams

Numerade Educator

Problem 75

Coal, which is primarily carbon, can be converted to natural gas, primarily $\mathrm{CH}_{4}$, by this exothermic reaction.
$$
\mathrm{C}(s)+2 \mathrm{H}_{2}(g) \rightleftharpoons \mathrm{CH}_{4}(g)
$$
If this reaction mixture is at equilibrium, predict the effect (shift right, shift left, or no effect) of these changes.
(a) adding more $\mathrm{C}$ to the reaction mixture
(b) adding more $\mathrm{H}_{2}$ to the reaction mixture
(c) raising the temperature of the reaction mixture
(d) lowering the volume of the reaction mixture
(e) adding a catalyst to the reaction mixture

Lottie Adams

Numerade Educator

Problem 76

Coal can be used to generate hydrogen gas (a potential fuel) by this endothermic reaction.
$$
\mathrm{C}(s)+\mathrm{H}_{2} \mathrm{O}(g) \rightleftharpoons \mathrm{CO}(g)+\mathrm{H}_{2}(g)
$$
If this reaction mixture is at equilibrium, predict the effect (shift right, shift left, or no effect) of these changes.
(a) adding more $C$ to the reaction mixture
(b) adding more $\mathrm{H}_{2} \mathrm{O}(g)$ to the reaction mixture
(c) raising the temperature of the reaction mixture
(d) increasing the volume of the reaction mixture
(e) adding a catalyst to the reaction mixture

Lottie Adams

Numerade Educator

Problem 77

For each compound, write an equation showing how the compound dissolves in water and write an expression for $K_{\mathrm{sp}}$
(a) $\mathrm{CaSO}_{4}$
(b) $\mathrm{AgCl}$
(c) $\mathrm{CuS}$
(d) $\mathrm{FeCO}_{3}$

Lottie Adams

Numerade Educator

Problem 78

For each compound, write an equation showing how the compound dissolves in water and write an expression for $K_{\mathrm{sp}}$
(a) $\mathrm{Mg}(\mathrm{OH})_{2}$
(b) $\mathrm{FeCO}_{3}$
(c) $\mathrm{PbS}$
(d) $\mathrm{PbSO}_{4}$

Lottie Adams

Numerade Educator

Problem 79

Determine what is wrong with the $K_{\mathrm{sp}}$ expression for $\mathrm{Fe}(\mathrm{OH})_{2}$ and correct it.
$$
K_{\mathrm{sp}}=\left[\mathrm{Fe}^{2+}\right]\left[\mathrm{OH}^{-}\right]
$$

Lottie Adams

Numerade Educator

Problem 80

Determine what is wrong with the $K_{\mathrm{sp}}$ expression for $\mathrm{Ba}(\mathrm{OH})_{2}$ and correct it.
$$
K_{\mathrm{sp}}=\frac{\left[\mathrm{Ba}(\mathrm{OH})_{2}\right]}{\left[\mathrm{Ba}^{2+}\right]\left[\mathrm{OH}^{-}\right]^{2}}
$$

Lottie Adams

Numerade Educator

Problem 81

A saturated solution of $\mathrm{MgF}_{2}$ has $\left[\mathrm{Mg}^{2+}\right]=2.6 \times$
$10^{-4} \mathrm{M}$ and $\left[\mathrm{F}^{-}\right]=5.2 \times 10^{-4} \mathrm{M}$. What is the value
of $K_{\mathrm{sp}}$ for $\mathrm{MgF}_{2} ?$

Lottie Adams

Numerade Educator

Problem 82

Asaturated solution of $\mathrm{Ag}_{2} \mathrm{CO}_{3}$ has $\left[\mathrm{Ag}^{+}\right]=0.232 \times 10^{-3} \mathrm{M}$
and $\left[\mathrm{CO}_{3}^{2-}\right]=0.116 \times 10^{-3} \mathrm{M}$. What is the $\mathrm{K}_{\mathrm{sp}}$ for $\mathrm{Ag}_{2} \mathrm{CO}_{3} ?$

David Collins

Numerade Educator

Problem 83

A saturated solution of $\mathrm{PbSO}_{4}$ has $\left[\mathrm{Pb}^{2+}\right]=1.35 \times 10^{-4} \mathrm{M}$
What is the concentration of $\mathrm{SO}_{4}{ }^{2-} ?$

Lottie Adams

Numerade Educator

Problem 84

A saturated solution of $\mathrm{Al}_{2}\left(\mathrm{SO}_{4}\right)_{3}$ has $\left[\mathrm{Al}^{3+}\right]=2.128 \mathrm{M}$.
What is the concentration of $\mathrm{SO} 4^{2-}$ ?

Lottie Adams

Numerade Educator

Problem 85

Calculate the molar solubility of $\mathrm{CaCO}_{3}$

Lottie Adams

Numerade Educator

Problem 86

Calculate the molar solubility of $\mathrm{PbS}$.

Lottie Adams

Numerade Educator

Problem 87

Calculate the molar solubility of $\mathrm{PbSO}_{4}$

David Collins

Numerade Educator

Problem 88

Calculate the molar solubility of $\operatorname{CuI}\left(K_{\mathrm{sp}}=1.27 \times 10^{-12}\right)$

Lottie Adams

Numerade Educator

Problem 89

Complete the table. Assume that all concentrations are equilibrium concentrations in moles per liter, M.

William Mills

Numerade Educator

Problem 90

Complete the table. Assume that all concentrations are equilibrium concentrations in moles per liter, M.

William Mills

Numerade Educator

Problem 91

Consider the reaction.
$$
\begin{array}{c}
\mathrm{CO}(g)+\mathrm{Cl}_{2}(g) \rightleftharpoons \mathrm{COCl}_{2}(g) \\
K_{\mathrm{eq}}=6.17 \times 10^{-2} \text {at } 25^{\circ} \mathrm{C}
\end{array}
$$
A 3.67-L flask containing an equilibrium reaction mixture has $\left[\mathrm{H}_{2}\right]=0.104 \mathrm{M}$ and $\left[\mathrm{I}_{2}\right]=0.0202 \mathrm{M} .$ What mass of $\mathrm{HI}$
in grams is in the equilibrium mixture?

Lottie Adams

Numerade Educator

Problem 92

Consider the reaction.
$$
\begin{array}{c}
2 \mathrm{NOBr}(g) \rightleftharpoons \mathrm{Br}_{2}(g)+2 \mathrm{NO}(g) \\
K_{\mathrm{eq}}=14.2 \times 10^{-3}
\end{array}
$$
A 1.88-L flask containing an equilibrium mixture has $\left[\mathrm{Br}_{2}\right]=0.1 \mathrm{M}$ and $[\mathrm{NO}]=0.3 \mathrm{M}$. How much $\mathrm{NOBr}$ in
grams is in the equilibrium mixture?

Lottie Adams

Numerade Educator

Problem 93

Consider the reaction.
$$
\begin{array}{c}
\mathrm{CO}(g)+\mathrm{Cl}_{2}(g) \rightleftharpoons \mathrm{COCl}_{2}(g) \\
K_{\mathrm{eq}}=6.17 \times 10^{-2} \text {at } 25^{\circ} \mathrm{C}
\end{array}
$$
A 3.67-L flask containing an equilibrium reaction mixture has $\left[\mathrm{H}_{2}\right]=0.104 \mathrm{M}$ and $\left[\mathrm{I}_{2}\right]=0.0202 \mathrm{M} .$ What mass of $\mathrm{HI}$
in grams is in the equilibrium mixture?

Lottie Adams

Numerade Educator

Problem 94

Consider the reaction.
$$
\begin{array}{c}
2 \mathrm{NOBr}(g) \rightleftharpoons \mathrm{Br}_{2}(g)+2 \mathrm{NO}(g) \\
K_{\mathrm{eq}}=14.2 \times 10^{-3}
\end{array}
$$
A 1.88-L flask containing an equilibrium mixture has $\left[\mathrm{Br}_{2}\right]=0.1 \mathrm{M}$ and $[\mathrm{NO}]=0.3 \mathrm{M} .$ How much $\mathrm{NOBr}$ in
grams is in the equilibrium mixture?

Lottie Adams

Numerade Educator

Problem 95

This reaction is exothermic.
$$
\mathrm{C}_{2} \mathrm{H}_{4}(g)+\mathrm{Cl}_{2}(g) \rightleftharpoons \mathrm{C}_{2} \mathrm{H}_{4} \mathrm{Cl}_{2}(g)
$$
If you were a chemist trying to maximize the amount of $\mathrm{C}_{2} \mathrm{H}_{4} \mathrm{Cl}_{2}$ produced, which of the following might you try? Assume that the reaction mixture reaches equilibrium.
(a) increasing the reaction volume
(b) removing $\mathrm{C}_{2} \mathrm{H}_{4} \mathrm{Cl}_{2}$ from the reaction mixture as it forms
(c) lowering the reaction temperature
(d) adding $\mathrm{Cl}_{2}$

Lottie Adams

Numerade Educator

Problem 96

Consider the reaction.
$$
\mathrm{I}_{2}(a q)+\mathrm{I}^{-}(a q) \rightleftharpoons \mathrm{I}_{3}^{-}(a q)
$$
If you were a chemist trying to maximize the amount of $\mathrm{I}_{3}^{-}$ produced, which of the following might you try? Assume that the reaction mixture reaches equilibrium.
(a) addition of $\mathrm{I}_{2}$
(b) addition of water
(c) to trap the formed $\mathrm{I}_{3}^{-}$ with starch
(d) evaporate water from the solution

Teesta Dasgupta

Teesta Dasgupta

University of Pittsburgh - Main Campus

Problem 97

Calculate the molar solubility of CuS. How many grams of CuS are present in 15.0 L of a saturated CuS solution?

Lottie Adams

Numerade Educator

Problem 98

Calculate the molar solubility of $\mathrm{CaSO}_{4} .$ How many grams of $\mathrm{CaSO}_{4}$ can be dissolved in $50 \mathrm{~mL}$ of water?

Adriano Chikande

Adriano Chikande

Numerade Educator

Problem 99

A sample of tap water is found to be $0.025 \mathrm{M}$ in $\mathrm{Ca}^{2+}$. If $105 \mathrm{mg}$ of $\mathrm{Na}_{2} \mathrm{SO}_{4}$ is added to $100.0 \mathrm{~mL}$ of the tap water, will any CaSO $_{4}$ precipitate out of solution?

Lottie Adams

Numerade Educator

Problem 100

If $50.0 \mathrm{mg}$ of $\mathrm{Na}_{2} \mathrm{CO}_{3}$ are added to $150.0 \mathrm{~mL}$ of a solution that is $1.5 \times 10^{-3} \mathrm{M}$ in $\mathrm{Mg}^{2+}$, will any $\mathrm{MgCO}_{3}$ precipitate from the solution?

Lottie Adams

Numerade Educator

Problem 101

The solubility of $\mathrm{CaCrO}_{4}$ at $25^{\circ} \mathrm{C}$ is $4.15 \mathrm{~g} / \mathrm{L}$. Calculate $K_{\mathrm{sp}}$ for $\mathrm{CaCrO}_{4}$

Lottie Adams

Numerade Educator

Problem 102

The solubility of $\mathrm{FeF}_{3}$ at $25^{\circ} \mathrm{C}$ is $0.91 \mathrm{~g} / \mathrm{L}$. Calculate $\mathrm{K}_{\mathrm{sp}}$ for $\mathrm{FeF}_{3}$.

Lottie Adams

Numerade Educator

Problem 103

Consider the reaction:
$$
\mathrm{CaCO}_{3} \rightleftharpoons \mathrm{CaO}(s)+\mathrm{CO}_{2}(g)
$$
A sample of $\mathrm{CaCO}_{3}$ is placed into a sealed $0.500-\mathrm{L}$ container and heated to $550 \mathrm{~K}$ at which the equilibrium constant is $4.1 \times 10^{-4}$. When the reaction has come to equilibrium, what mass of solid $\mathrm{CaO}$ is in the container? (Assume that the sample of $\mathrm{CaCO}_{3}$ was large enough that equilibrium could be achieved.)

Lottie Adams

Numerade Educator

Problem 104

Consider the reaction:
$$
\mathrm{NH}_{4} \mathrm{HS}(s) \rightleftharpoons \mathrm{NH}_{3}(g)+\mathrm{H}_{2} \mathrm{~S}(g)
$$
A sample of pure $\mathrm{NH}_{4} \mathrm{HS}$ is placed in a sealed $2.0-\mathrm{L}$ container and heated to $550 \mathrm{~K}$ at which the equilibrium constant is $3.5 \times 10^{-3}$. Once the reaction reaches equilibrium, what mass of $\mathrm{NH}_{3}$ is in the container? (Assume that the sample of $\mathrm{NH}_{4}$ HS was large enough that equilibrium could be achieved.)

Julian Taurozzi

Julian Taurozzi

Numerade Educator

Problem 105

A 2.55-L solution is $0.115 \mathrm{M}$ in $\mathrm{Mg}^{2+}$. If $\mathrm{K}_{2} \mathrm{CO}_{3}$ is added to the solution in order to precipitate the magnesium, what minimum mass of $\mathrm{K}_{2} \mathrm{CO}_{3}$ is required to get a precipitate?

LJ

Lena Jake

Numerade Educator

Problem 106

SaOH is added to $122 \mathrm{~mL}$ of a $0.17 \mathrm{M}$ solution of $\mathrm{Pb}^{4+}$ to precipitate the lead as $\mathrm{Pb}(\mathrm{OH})_{4} .$ What minimum amount of $\mathrm{NaOH}$ would be required to precipitate all the lead?

Adriano Chikande

Adriano Chikande

Numerade Educator

Problem 107

$\mathrm{H}_{2}$ and $\mathrm{I}_{2}$ are combined in a flask and allowed to react according to the reaction:
$$
\mathrm{H}_{2}(g)+\mathrm{I}_{2}(g) \rightleftharpoons 2 \mathrm{HI}(g)
$$
Examine the figures (sequential in time) and determine which figure represents the point where equilibrium is reached.

Lottie Adams

Numerade Educator

Problem 108

Ethene $\left(\mathrm{C}_{2} \mathrm{H}_{4}\right)$ can be halogenated by the reaction:
$$
\mathrm{C}_{2} \mathrm{H}_{4}(g)+\mathrm{X}_{2}(g) \rightleftharpoons \mathrm{C}_{2} \mathrm{H}_{4} \mathrm{X}_{2}(g)
$$
where $X_{2}$ can be $\mathrm{Cl}_{2}, \mathrm{Br}_{2},$ or $\mathrm{I}_{2} .$ Examine the figures representing equilibrium concentrations of this reaction at the same temperature for the three different halogens. Rank the equilibrium constants for these three reactions from largest to smallest.

Lottie Adams

Numerade Educator

Problem 109

One of the main components of hard water is $\mathrm{CaCO}_{3}$. When hard water evaporates, some of the $\mathrm{CaCO}_{3}$ is left behind as a white mineral deposit. Plumbing fixtures in homes with hard water often acquire these deposits over time. Toilets, for example, may develop deposits at the water line as the water in the toilet slowly evaporates away. If water is saturated with $\mathrm{CaCO}_{3},$ how much of it has to evaporate to deposit $0.250 \mathrm{~g}$ of $\mathrm{CaCO}_{3}$ ? Hint: Begin by using $K_{\mathrm{sp}}$ for $\mathrm{CaCO}_{3}$ to determine its solubility.

Lottie Adams

Numerade Educator

Problem 110

Consider the following generic equilibrium in which a solid reactant is in equilibrium with a gaseous product:
$$
\mathrm{A}(s) \rightleftharpoons \mathrm{B}(g)
$$
These diagrams represent the reaction mixture at the following points: (a) initially; (b) after a short period of time has passed; and (c) at equilibrium.

Ronald Prasad

Numerade Educator

Problem 111

A certain town gets its water from an underground aquifer that contains water in equilibrium with calcium carbonate limestone.
(a) What is the symbol for the equilibrium constant that describes calcium carbonate dissolving in water? What is the numerical value?
(b) Calculate the molar solubility of calcium carbonate.
(c) If an entire coffee cup full of water (about $200 \mathrm{~mL}$ ) evaporated on your desk over spring break, how many grams of calcium carbonate would be left behind?

Md Mohibullah

Auburn University Main Campus

Problem 112

The reaction $\mathrm{A}+\mathrm{B} \longrightarrow 2 \mathrm{C}$ has an equilibrium constant of 16
(a) Without doing any calculations, at equilibrium will there be more $\mathrm{A}, \mathrm{B},$ or $\mathrm{C}$ around? Explain your answer.

Preeti Kumari

Numerade Educator

Problem 113

Describe three ways a reaction at equilibrium can be changed such that it is no longer in equilibrium. For each case, indicate which way the reaction will shift to return to equilibrium.

Steven Swee

Numerade Educator