Q: For the reaction $$\mathrm{2H_2S(g) \rightleftharpoons 2H_2(g) + S_2$(g)}$$, if $$K_p = 2.4 \times 10$$^{-4}$$ at 1073 K and a reaction mixture has P$$_{$$H_2$$} = 0.112$$ atm, P$$_{$$S_2$$} = 0.055$$ atm, and P$$_{H_2S} = 0.445$$ atm, what is the value of Q$ and in which direction will the reaction proceed?

$$Q = 3.5 \times 10$$^{-3}$$; the reaction will proceed to the left.

Question 1

Which of the following best describes the state of dynamic chemical equilibrium as shown in the provided graph for the reaction $$\mathrm{H_2$(g) + I_2$(g) \rightleftharpoons 2HI(g)}$$?

Accepted Answer

The concentrations of all species remain constant because the rates of the forward and reverse reactions are equal.

Question 2

For the reaction $$\mathrm{H_2$(g) + I_2$(g) \rightleftharpoons 2HI(g)}$$, which of the following statements is true at dynamic equilibrium?

Accepted Answer

The rates of the forward and reverse reactions are equal, but the concentrations of reactants and products are not necessarily equal.

Question 3

Given the reaction $$\mathrm{N_2$(g) + 3H_2(g) ightleftharpoons 2NH_3(g)}$$, the equilibrium constant $$K_c is$$ $$3.7 	imes 10^8$ at 298 K. What does this value of K_c$ indicate about the composition of the equilibrium mixture?

Accepted Answer

The mixture contains mostly products.

Question 4

For the reaction $$\mathrm{CO(g) + 3H_2(g) \rightleftharpoons CH_4$(g) + H_2O(g)}$$, the equilibrium constant expression $$K_c is$$:

Accepted Answer

$$K_c = \frac{[CH_4$][H_2O]}{[CO][H_2$]^3}$$

Question 5

If the coefficients in a balanced chemical equation are multiplied by a factor of 2, how does the new equilibrium constant $$K_{new}$$ relate to the original $$K_c$$?

Accepted Answer

$$K_{new} = K_c^2$

Question 6

For the reaction $$\mathrm{2H_2S(g) ightleftharpoons 2H_2(g) + S_2$(g)}$$, if $$K_p = 2.4 	imes 10$$^{-4}$$ at 1073 K and a reaction mixture has P$$_{$$H_2$$} = 0.112$$ atm, P$$_{$$S_2$$} = 0.055$$ atm, and P$$_{H_2S} = 0.445$$ atm, what is the value of Q$ and in which direction will the reaction proceed?

Accepted Answer

$$Q = 3.5 	imes 10$$^{-3}$$; the reaction will proceed to the left.

Question 7

Which of the following is NOT included in the equilibrium constant expression for the reaction $$\mathrm{$$CaCO_3$$(s) \rightleftharpoons CaO(s) + CO_2$(g)}$$?

Accepted Answer

$$[$$CaCO_3$$]$$

Question 8

For the general reaction $$\mathrm{aA + bB \rightleftharpoons cC + dD}$$, the relationship between $$K_p$$ and $$K_c is $$given by:

Accepted Answer

$$K_p = K_c (RT$$)^{\Delta n}$$

Question 9

If a chemical equation is reversed, how does the new equilibrium constant $$K'$$ relate to the original equilibrium constant $$K$$?

Accepted Answer

$$K' = \frac{1}{K}$$

Question 10

A reaction mixture initially contains only reactants. What is the value of the reaction quotient $$Q at $$this point?

Accepted Answer

$$Q = 0$$

Question 11

Which of the following best explains why the concentrations of pure solids and pure liquids are not included in equilibrium constant expressions?

Accepted Answer

Their concentrations remain constant and do not affect the equilibrium position.

Question 12

For the reaction $$\mathrm{aA + bB \rightleftharpoons cC + dD}$$, if $$Q \u003c K$$, what will happen to the reaction mixture?

Accepted Answer

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

Question 13

Which of the following statements about the equilibrium constant $$K is $$correct?

Accepted Answer

The value of $$K is $$temperature dependent.

Question 14

If two chemical equations are added to yield a net reaction, how is the equilibrium constant for the net reaction ($$K_{net}) $$determined?

Accepted Answer

$$K_{net} is $$the product of the equilibrium constants of the individual reactions.

Question 15

A catalyst is added to a reaction mixture at equilibrium. What effect does this have on the position of equilibrium and the value of the equilibrium constant?

Accepted Answer

There is no effect on the position of equilibrium or the value of $$K.$$

Question 16

For the reaction $$\mathrm{N_2$(g) + 3H_2(g) ightleftharpoons 2NH_3(g)}$$, $$\Delta n = -2. If$$ $$K_c = 3.7 	imes 10^8$ at 298 K, what is the correct expression to calculate K_p$?

Accepted Answer

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

Question 17

Which of the following best describes a heterogeneous equilibrium?

Accepted Answer

Reactants and products are in different phases.

Chapter 16 lecture 1

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