Question 1

Which of the following best describes the condition of chemical equilibrium for the reaction $$\mathrm{N_2$ + 3H_2 \rightleftharpoons 2NH_3} as $$shown in the first image?

Accepted Answer

The concentrations of reactants and products stop changing because the forward and reverse reaction rates are equal.

Question 2

For the reaction $$\mathrm{$$CaCO_3$$(s) \rightleftharpoons CaO(s) + CO_2$(g)}$$ depicted in the second image, which of the following statements is true about the equilibrium constant expression?

Accepted Answer

$$K_p = P_{CO_2$}$$

Question 3

Le Chatelier's Principle, as illustrated in the third image, predicts that if more $$\mathrm{CO_2$} is $$added to the system $$\mathrm{$$CaCO_3$$(s) \rightleftharpoons CaO(s) + CO_2$(g)}$$, the equilibrium will:

Accepted Answer

Shift to produce more $$\mathrm{$$CaCO_3$$}$$

Question 4

What does the double arrow $$\rightleftharpoons (as $$shown in the fourth image) indicate about a chemical reaction?

Accepted Answer

The reaction can proceed in both the forward and reverse directions.

Question 5

For the reaction $$\mathrm{N_2$ + 3H_2 \rightleftharpoons 2NH_3}$$, if the equilibrium constant $$K is $$much greater than 1, which statement is correct?

Accepted Answer

The concentration of $$\mathrm{NH_3$} is $$much greater than that of $$\mathrm{N_2$}$$ and $$\mathrm{H_2$} at $$equilibrium.

Question 6

Given the reaction $$\mathrm{2SO_3(g) \rightleftharpoons 2SO_2(g) + O_2$(g)}$$, what will happen if the volume of the container is decreased at constant temperature?

Accepted Answer

The equilibrium will shift to the left, producing more $$\mathrm{SO_3$}.$$

Question 7

Which of the following is NOT included in the equilibrium constant expression for a heterogeneous equilibrium?

Accepted Answer

Concentration of a pure solid

Question 8

For the reaction $$\mathrm{H_2$(g) + Cl_2$(g) \rightleftharpoons 2HCl(g)}$$ with $$K = 348$$, if the initial concentrations are $$[H_2$] = 2.0\,M$$, $$[Cl_2$] = 2.0\,M$$, and $$[HCl] = 1.0\,M$$, what is the equilibrium concentration of $$\mathrm{HCl}$$?

Accepted Answer

$$4.5\,M$$

Question 9

Which of the following reactions will have $$K_p = K$$?

Accepted Answer

$$\mathrm{C(s) + O_2$(g) \rightleftharpoons CO_2$(g)}$$

Question 10

If the reaction $$\mathrm{N_2$(g) + 3H_2(g) \rightleftharpoons 2NH_3(g) + heat} is at $$equilibrium, what will happen if the temperature is increased?

Accepted Answer

The equilibrium will shift to the left, producing more $$\mathrm{N_2$}$$ and $$\mathrm{H_2$}.$$

Question 11

For the reaction $$\mathrm{2NO_2(g) \rightleftharpoons N_2O_4(g)}$$, what happens if a noble gas is added at constant volume and temperature?

Accepted Answer

There is no shift in equilibrium.

Question 12

A reaction mixture initially contains only $$\mathrm{NH_3$}$$ for the reaction $$\mathrm{N_2$ + 3H_2 \rightleftharpoons 2NH_3}. $$What will happen as the system approaches equilibrium?

Accepted Answer

The concentrations of $$\mathrm{N_2$}$$ and $$\mathrm{H_2$}$$ will increase.

Question 13

For the reaction $$\mathrm{CH_4$(g) + H_2O(g) ightleftharpoons CO(g) + 3H_2(g)}$$ with $$K_p = 1.8 	imes 10$$^{-7}$$ and initial pressures P$$_{$$CH_4$$} = 1.40$$ atm, P$$_{H_2O} = 2.30$$ atm, P$$_{CO} = 1.60$$ atm, what is the equilibrium pressure of $$\mathrm{$$H_2$$}$$?

Accepted Answer

0.0072 atm

Question 14

If $$K \u003e Q$$ for a reaction mixture, what will happen as the system moves toward equilibrium?

Accepted Answer

The reaction will shift to the right, forming more products.

Question 15

Which of the following changes will increase the amount of $$\mathrm{CaC_2O_4(s)} in a $$solution at equilibrium, given the reactions: $$\mathrm{Ca$$^{2+}$$ + C_2O_4$$^{2-}$$ \rightleftharpoons CaC_2O_4(s)}$$, $$\mathrm{H_2C_2O_4 \rightleftharpoons H^+ + HC_2O_4^-}$$, $$\mathrm{HC_2O_4^- \rightleftharpoons H^+ + C_2O_4$$^{2-}$$}$$?

Accepted Answer

Adding NaOH

Question 16

If the equilibrium constant for a reaction is multiplied by 2, what happens to the value of $$K$$?

Accepted Answer

It is squared.

Question 17

For the reaction $$\mathrm{$$PCl_5$$(g) \rightleftharpoons $$PCl_3$$(g) + Cl_2$(g)}$$, if you start with 0.5 atm $$\mathrm{$$PCl_5$$}$$ and the total pressure at equilibrium is 0.84 atm, what is the value of $$K_p$$?

Accepted Answer

$$0.72$$

Question 18

Which of the following best describes the effect of increasing temperature on the equilibrium constant $$K$$ for an endothermic reaction?

Accepted Answer

The value of $$K$$ increases.

Chemical Equilibrium: Principles, Calculations, and Applications

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