Equilibrium MCQ

Question 1. The equilibrium expression, K_c= [C0₂] represents the reaction.

Answer: 1.(b) Caco₃ — Cao + Co₂

Question 2. Hydrogen molecule (H₂) can be dissociated into hydrogen atoms (H). Which one of the following changes will not increase the number of atoms present at equilibrium?

• (a) adding H atoms
• (b) increasing the temperature
• (c) increasing the total pressure
• (d) increasing the volume of the container

Answer: 2.(c) increasing the total pressure

Question 3. What is the expression for K_eq? for the reaction

Answer  3.(c)

Question 4. A catalyst will increase the rate of a chemical reaction by

• (a) shifting the equilibrium to the right
• (b) shifting the equilibrium to the left
• (c) lowering the activation energy
• (d) increasing the activation energy

Answer:  4.(c) lowering the activation energy

Question 5. What is the correct expression for the representation of the solubility product constant of Ag₂ Cr0₄ ?

Answer:  5.(a)

Question 6. In a closed system

Answer: 6.(d)

Question 7. H₂+ S ——->H₂S + energy. In this reversible reaction, select the factor which will shift the equilibrium to the right.

• (a) adding heat
• (b) adding H₂S
• (c) blocking hydrogen gas reaction
• (d) removing hydrogen sulphide gas

Answer: 7.(a) adding heat

Question 8. What effect does a catalyst have on the equilibrium position of a reaction?

• (a) a catalyst favours the formation of products
• (b) a catalyst favours the formation of reactants
• (c) a catalyst does not change the equilibrium position of a reaction
• (d) a catalyst may favour reactants or product formation, depending upon the directiofi in which the reaction is written.

Answer:  8.(c) a catalyst does not change the equilibrium position of a reaction

Question 9. A chemist dissolves an excess of BaSO₄ in pure water at 25°C if its K_sp= 1 x 10^-10  what is the concentration of barium in the water?

• (a) 10^-4 M
• (b) 10^-5 M
• (C) 10^-15 M
• (d) 10^-6 M

Answer:  9.(c) 10^-15 M

Question 10. If in a mixture where Q = k is combined, then what happens?

• (a) the reaction shift towards products
• (b) the reaction shift towards reactants
• (c) nothing appears to happen, but forward and reverse are continuing at the same rate
• (d) nothing happens

Answer: 10.(c) nothing appears to happen, but forward and reverse are continuing at the same rate