Question 1

Which of the following statements about dynamic equilibrium is FALSE?

Accepted Answer

At equilibrium, the concentrations of reactants and products are equal.

Question 2

For the reaction $$\mathrm{N_2O_4(g) \rightleftharpoons 2NO_2(g)}$$, the equilibrium constant $$K is 0.36 at a $$certain temperature. If a mixture initially contains $$[\mathrm{N_2O_4}] = 1.0\ \mathrm{M}$$ and $$[\mathrm{NO_2$}] = 0.0\ \mathrm{M}$$, what will happen as the system approaches equilibrium?

Accepted Answer

The concentration of $$\mathrm{NO_2$}$$ will increase and $$\mathrm{N_2O_4}$$ will decrease.

Question 3

Which of the following best describes the effect of adding more $$\mathrm{O_2$} to $$the equilibrium system $$\mathrm{Hb} + \mathrm{O_2$} \rightleftharpoons \mathrm{$$HbO_2$$} in $$the lungs?

Accepted Answer

The equilibrium shifts to the right, producing more $$\mathrm{$$HbO_2$$}.$$

Question 4

For the reaction $$\mathrm{A} \rightleftharpoons \mathrm{B}$$, $$K = 10. If $$the initial concentrations are $$[\mathrm{A}] = 1.1\ \mathrm{M}$$ and $$[\mathrm{B}] = 0.0\ \mathrm{M}$$, which statement is true at equilibrium?

Accepted Answer

The reaction mixture contains $$[\mathrm{A}] = 0.1\ \mathrm{M}$$ and $$[\mathrm{B}] = 1.0\ \mathrm{M}.$$

Question 5

Which of the following changes will NOT affect the position of equilibrium for a reaction involving only gases?

Accepted Answer

Adding an inert gas at constant volume.

Question 6

For the reaction $$\mathrm{2SO_2(g) + O_2$(g) \rightleftharpoons 2SO_3(g)}$$, how will the equilibrium shift if the volume of the container is decreased?

Accepted Answer

The equilibrium will shift to the right, toward more $$\mathrm{SO_3$}.$$

Question 7

Which of the following is TRUE regarding the equilibrium constant $$K$$ for a reaction?

Accepted Answer

It changes if the temperature changes.

Question 8

For the reaction $$\mathrm{C(s) + CO_2$(g) \rightleftharpoons 2CO(g)}$$, which substances are included in the equilibrium constant expression?

Accepted Answer

Only $$\mathrm{CO_2$}$$ and $$\mathrm{CO}.$$

Question 9

If the equilibrium constant for a reaction is $$K = 0.010$$, what is the equilibrium constant for the reverse reaction?

Accepted Answer

$$K = 100$$

Question 10

Which of the following best describes the effect of increasing temperature on an exothermic reaction at equilibrium?

Accepted Answer

The equilibrium shifts to the left and $$K$$ decreases.

Question 11

A reaction mixture at equilibrium contains $$[A] = 1.0\ \mathrm{M}. $$For the reaction $$2A \rightleftharpoons B$$, what is the concentration of $$B if$$ $$K = 2.0$$?

Accepted Answer

$$[B] = 2.0\ \mathrm{M}$$

Question 12

Which of the following is TRUE about the reaction quotient $$Q$$?

Accepted Answer

If $$Q \u003c K$$, the reaction will proceed in the forward direction.

Question 13

Which of the following disturbances will cause the equilibrium to shift to the right for the exothermic reaction $$2NOCl(g) \rightleftharpoons 2NO(g) + Cl_2$(g)$$?

Accepted Answer

Adding $$NOCl to $$the reaction mixture.

Question 14

Which of the following is NOT a valid way to disturb a chemical equilibrium?

Accepted Answer

Adding a catalyst.

Question 15

For the reaction $$\mathrm{N_2$(g) + 3H_2(g) \rightleftharpoons 2NH_3(g)}$$, what will happen if the volume of the container is increased?

Accepted Answer

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

Question 16

Which of the following is TRUE about the concentrations of pure solids and liquids in equilibrium expressions?

Accepted Answer

They are not included because their concentrations do not change.

Question 17

For the reaction $$\mathrm{A(g) + B(g) \rightleftharpoons C(g)}$$, $$K_p$$ and $$K_c$$ are equal under which condition?

Accepted Answer

When the total number of moles of gas is the same on both sides of the equation.

Chapter 16: Chemical Equilibrium – Study Notes

Study Guide - Practice Questions

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