17.1 The Equilibrium Law

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

A. K remains unchanged

B. K increases

C. K decreases

D. K becomes zero

In the context of Le Chatelier's principle, what is the response of a system at equilibrium when stress is applied?

A. The system shifts to increase the stress

B. The system shifts to decrease the stress

C. The system remains unchanged

D. The system reaches a new equilibrium immediately

Which of the following is true regarding the relationship between Gibbs free energy change (Delta G) and the equilibrium constant (K)?

A. Delta G is positive when K > 1

B. Delta G is negative when K < 1

C. Delta G is zero when K = 1

D. Delta G and K are not related

For a given reaction at equilibrium, if the concentration of reactants is increased, what will happen to the equilibrium position?

A. It will shift to the right

B. It will shift to the left

C. It will remain unchanged

D. It will depend on the temperature

How does an increase in pressure affect the equilibrium position of a gaseous reaction that produces fewer moles of gas?

A. Shifts to the right

B. Shifts to the left

C. No effect

D. The direction of shift cannot be determined

a) Explain the principle of Le Chatelier's principle and how it can be used to predict the effect of changes on the equilibrium position of a reaction. [3]

b) A system at equilibrium is subjected to an increase in pressure. Describe how this change would affect the position of equilibrium for a reaction that produces fewer moles of gas. [2]

a) Describe the relationship between Gibbs free energy change (ΔG) and the equilibrium constant (K) for a reaction. [3]

b) If ΔG for a reaction is positive, what can be inferred about the spontaneity of the reaction and the value of K? [2]

a) The Haber process is an industrial method for producing ammonia. Describe how the principles of equilibrium are utilised in this process to maximise the yield of ammonia. [3]

b) In the context of the Haber process, explain the effect of increasing the temperature on the equilibrium position and the rate of reaction. [2]

a) Describe the effect of a catalyst on the rate of a reaction and its impact on the position of equilibrium. [2]

b) Consider a reaction that is endothermic in the forward direction. Predict the effect of decreasing the temperature on the equilibrium position. [2]

c) How does the value of the equilibrium constant, K, change for the above reaction when the temperature is decreased? [2]

a) Explain the relationship between stress and response in equilibrium systems using Le Chatelier's principle. [3]

b) If the concentration of products in a system at equilibrium is increased, predict the direction in which the system will shift. [1]

c) How would the addition of an inert gas at constant volume affect the position of equilibrium? [2]