30 Chemical Equilibrium Practice Problems for DAT Prep

CHEMICAL EQUILIBRIUM TEST 1

1 / 5

Which of the following is a reversible reaction?

A. 2C₂H₆(g) + 7O₂(g) → 4CO₂(g) + 6H₂O(l)

B. 4HNO₃(aq) + Cu(s) → Cu(NO₃)₂(aq) + 2NO₂(g) + 2H₂O(l)

C. LiOH(aq) + HI(aq) → Li(aq) + H₂O(l)

D. Pb(NO₃)₂(aq) + 2KI(aq) → 2KNO₃(aq) + PBI₂(s)

E. CH₄(g) + H₂O(g) → CO(g) + 3H₂(g)

Explanation:

A, B, C, and D are irreversible reactions, which are the combustion reaction, gas production from the reaction between an acid and a metal, neutralization between a strong acid and a strong base, and precipitation reaction.

2 / 5

Which of the following is a correct statement about the equilibrium state of a reaction?

A. The equilibrium state is seen in both reversible and irreversible reactions.

B. At equilibrium, the rate of a forward reaction is faster than in a reverse reaction.

C. At equilibrium, both the forward and reverse reactions are stopped.

D. At equilibrium, the concentration of the reactant and the product is constant.

E. At equilibrium, the concentration of the reactant and the product is the same.

Explanation:

The equilibrium state is seen only in a reversible reaction and the rate of a forward and reverse reaction is the same. The forward and reverse reaction does not stop but the reaction rate remains constant. The concentration of the reactant and the product is not the same, but the concentration of the reactant and the product is constant.

3 / 5

Which of the following affects the equilibrium constant K_eq?

A. Concentration of reactants or products

B. Temperature

C. Catalysis

D. Reaction quotient (Q)

E. B and C

Explanation:

The equilibrium constant K_eq depends only on the temperature.

4 / 5

Which of the following is an INCORRECT statement?

A. Keq > 1 means that there are more products than reactants.