Q: Which equation correctly expresses the equilibrium constant $$K_c$$ for the reaction: $$16\ \mathrm{CH_3Cl}(g) + 8\ \mathrm{Cl_2$}(g) \rightleftharpoons 16\ \mathrm{CH_2Cl_2}(g) + 8\ \mathrm{H_2$}(g)$$?

$$K_c = \frac{[\mathrm{CH_2Cl_2}]^{16} \times [\mathrm{H_2$}]^{8}}{[\mathrm{CH_3Cl}]^{16} \times [\mathrm{Cl_2$}]^{8}}$$

Q: Given the reaction $$\mathrm{N_2$}(g) + 3\ \mathrm{H_2$}(g) \rightleftharpoons 2\ \mathrm{NH_3$}(g)$$ with $$K_c = 0.0602 at$$ $$298\ \mathrm{K}$$, $$R = 0.0821\ \mathrm{L\cdot atm/(mol\cdot K)}$$, what is the value of $$K_p$$?

$$K_p = K_c \times (RT$$)^{-2}$$

Q: For the reaction $$\mathrm{CH_4$}(g) + \mathrm{H_2O}(g) \rightleftharpoons \mathrm{CO}(g) + 3\ \mathrm{H_2$}(g)$$, $$K_p = 7.7 \times 10$$^{24}$$ at 298$$\ \mathrm{K}$$, R = 0.0821$$\ \mathrm{L\cdot atm/(mol\cdot K)}$$. What is the correct formula to convert K_p$ to K_c$?

$$K_c = K_p \times (RT$$)^{-2}$$

Question 1

Which real-world event led to the development of the Haber-Bosch process for ammonia synthesis?

Accepted Answer

The need for ammonia to produce explosives and fertilizers, leading to wars over guano deposits.

Question 2

Which equation correctly expresses the equilibrium constant $$K_c$$ for the reaction: $$16\ \mathrm{CH_3Cl}(g) + 8\ \mathrm{Cl_2$}(g) \rightleftharpoons 16\ \mathrm{CH_2Cl_2}(g) + 8\ \mathrm{H_2$}(g)$$?

Accepted Answer

$$K_c = \frac{[\mathrm{CH_2Cl_2}]^{16} 	imes [\mathrm{H_2$}]^{8}}{[\mathrm{CH_3Cl}]^{16} 	imes [\mathrm{Cl_2$}]^{8}}$$

Question 3

In the context of dynamic equilibrium, what does it mean when $$K \gg 1$$ for a reaction?

Accepted Answer

There are significantly more products than reactants at equilibrium.

Question 4

For the reaction $$2\ \mathrm{NO}(g) \rightleftharpoons \mathrm{N_2O_2}(g)$$, if the equilibrium constant for the reverse reaction is $$K_2$$, what is the equilibrium constant for the forward reaction?

Accepted Answer

$$K_1$$ = \frac{1}{$$K_2$$}$$

Question 5

Which of the following best describes the effect of a catalyst on a reaction at equilibrium?

Accepted Answer

A catalyst lowers the activation energy for both the forward and reverse reactions, but does not change the equilibrium position.

Question 6

Given the reaction $$\mathrm{N_2$}(g) + 3\ \mathrm{H_2$}(g) \rightleftharpoons 2\ \mathrm{NH_3$}(g)$$ with $$K_c = 0.0602 at$$ $$298\ \mathrm{K}$$, $$R = 0.0821\ \mathrm{L\cdot atm/(mol\cdot K)}$$, what is the value of $$K_p$$?

Accepted Answer

$$K_p = K_c 	imes (RT$$)^{-2}$$

Question 7

Which species are included in the equilibrium constant expression for the reaction $$\mathrm{Fe_2O_3}(s) + 3\ \mathrm{H_2$}(g) \rightleftharpoons 2\ \mathrm{Fe}(s) + 3\ \mathrm{H_2O}(l)$$?

Accepted Answer

Only $$\mathrm{H_2$}(g)$$, because solids and liquids do not appear in the equilibrium expression.

Question 8

For the reaction $$\mathrm{CH_4$}(g) + \mathrm{H_2O}(g) ightleftharpoons \mathrm{CO}(g) + 3\ \mathrm{H_2$}(g)$$, $$K_p = 7.7 	imes 10$$^{24}$$ at 298$$\ \mathrm{K}$$, R = 0.0821$$\ \mathrm{L\cdot atm/(mol\cdot K)}$$. What is the correct formula to convert K_p$ to K_c$?

Accepted Answer

$$K_c = K_p 	imes (RT$$)^{-2}$$

Question 9

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

Accepted Answer

SO3(g) + NO(g) \rightleftharpoons SO2(g) + NO2(g)

Question 10

If the equilibrium constant for $$2\ \mathrm{SO_2$}(g) + \mathrm{O_2$}(g) \rightleftharpoons 2\ \mathrm{SO_3$}(g) is 5.00 at 1300 K$$, and initial concentrations are $$[\mathrm{SO_2$}] = 6.00\ \mathrm{M}$$, $$[\mathrm{O_2$}] = 0.45\ \mathrm{M}$$, $$[\mathrm{SO_3$}] = 6.00\ \mathrm{M}$$, what is the state of the system?

Accepted Answer

The system is not at equilibrium and will shift toward the reactants.

Question 11

Which of the following best describes dynamic equilibrium in a chemical reaction?

Accepted Answer

The forward and reverse reactions occur at the same rate, resulting in no net change in concentrations.

Question 12

For the general reaction $$aA + bB \rightleftharpoons cC + dD$$, what is the correct equilibrium constant expression?

Accepted Answer

$$K_c = \frac{[C]^c 	imes [D]^d}{[A]^a 	imes [B]^b}$$

Question 13

Which of the following is a plausible reason why solids and liquids are not included in equilibrium constant expressions?

Accepted Answer

Their concentrations are essentially constant and do not affect the equilibrium position.

Question 14

A reaction has $$K \ll 1. $$What does this indicate about the equilibrium mixture?

Accepted Answer

There are significantly more reactants than products at equilibrium.

Question 15

Which of the following best explains why the Haber-Bosch process was revolutionary for agriculture?

Accepted Answer

It allowed for the industrial synthesis of ammonia, enabling large-scale fertilizer production.

Question 16

Given the following reactions and their equilibrium constants:
$$\mathrm{A}(g) + \mathrm{B}(g) \rightleftharpoons \mathrm{AB}(g),\ K_c = 0.24$$
$$\mathrm{AB}(g) + \mathrm{A}(g) \rightleftharpoons \mathrm{A_2B}(g),\ K_c = 3.8$$
What is the equilibrium constant for $$2\ \mathrm{A}(g) + \mathrm{B}(g) \rightleftharpoons \mathrm{A_2B}(g)$$?

Accepted Answer

$$K_c = 0.24 	imes 3.8 = 0.912$$

Question 17

Which of the following is the correct equilibrium constant expression for the reaction $$\mathrm{Fe_2O_3}(s) + 3\ \mathrm{H_2$}(g) \rightleftharpoons 2\ \mathrm{Fe}(s) + 3\ \mathrm{H_2O}(l)$$?

Accepted Answer

$$K = \frac{1}{[\mathrm{H_2$}]^3}$$

Question 18

If a reaction is held up by a rate-limiting step, what is the effect on the equilibrium?

Accepted Answer

The reaction still reaches equilibrium, but the rate-limiting step determines how quickly equilibrium is achieved.

Chemical Equilibrium and the Equilibrium Constant (Chapter 16, Part 1)

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