Chemistry Test Questions
1) At equilibrium, __________.
A) all chemical reactions have ceased
B) the rate constants of the forward and reverse reactions are equal
C) the rates of the forward and reverse reactions are equal
D) the value of the equilibrium constant is 1
E) the limiting reagent has been consumed
2) Which of the following expressions is the correct equilibrium-constant expression for the reaction below?
HF (s) + H2O (l) ⇌ H3O+ (aq) + F- (aq)
A) [HF][H2O] / [H3O+][F-]
B) 1 /[HF]
C) [H3O+][F-] / [HF][H2O]
D) [H3O+][F-] / [HF]
E) [F-] [H3O+]
3) The value of Keq for the equilibrium
H2 (g) + I2 (g) ⇌ 2 HI (g)
is 794 at 25 °C. At this temperature, what is the value of Keq for the equilibrium below?
HI (g) ⇌ 1/2 H2 (g) + 1/2 I2 (g)
A) 0.0013 B) 28 C) 0.035 D) 397 E)1588
4) Consider the following equilibrium.
2 SO2 (g) + O2 (g) ⇌ 2 SO3 (g)
The equilibrium cannot be established when __________ is/are placed in a 1.0-L container.
A) 0.75 mol SO2(g)
B) 0.25 mol of SO2 (g) and 0.25 mol of SO3 (g)
C) 1.0 mol SO3 (g)
D) 0.50 mol O2 (g) and 0.50 mol SO3 (g)
E) 0.25 mol SO2 (g) and 0.25 mol O2 (g)
5) The equilibrium-constant expression depends on the __________ of the reaction.
A) the quantities of reactants and products initially present
B) stoichiometry and mechanism
C) mechanism
D) stoichiometry
E) temperature
6) At elevated temperatures, molecular hydrogen and molecular bromine react to partially form hydrogen bromide:
H2 (g) + Br2 (g) ⇌ 2HBr (g)
A mixture of 0.682 mol of H2 and 0.440 mol of Br2 is combined in a reaction vessel with a volume of 2.00 L. At equilibrium at 700 K, there are 0.566 mol of H2 present. At equilibrium, there are __________ mol of Br2 present in the reaction vessel.
A) 0.440 B) 0.324 C) 0.000 D) 0.566 E) 0.232
7) At 200 °C, the equilibrium constant (Kp) for the reaction below is 2.40 × 103.
2NO (g) ⇌ N2
A) all chemical reactions have ceased
B) the rate constants of the forward and reverse reactions are equal
C) the rates of the forward and reverse reactions are equal
D) the value of the equilibrium constant is 1
E) the limiting reagent has been consumed
2) Which of the following expressions is the correct equilibrium-constant expression for the reaction below?
HF (s) + H2O (l) ⇌ H3O+ (aq) + F- (aq)
A) [HF][H2O] / [H3O+][F-]
B) 1 /[HF]
C) [H3O+][F-] / [HF][H2O]
D) [H3O+][F-] / [HF]
E) [F-] [H3O+]
3) The value of Keq for the equilibrium
H2 (g) + I2 (g) ⇌ 2 HI (g)
is 794 at 25 °C. At this temperature, what is the value of Keq for the equilibrium below?
HI (g) ⇌ 1/2 H2 (g) + 1/2 I2 (g)
A) 0.0013 B) 28 C) 0.035 D) 397 E)1588
4) Consider the following equilibrium.
2 SO2 (g) + O2 (g) ⇌ 2 SO3 (g)
The equilibrium cannot be established when __________ is/are placed in a 1.0-L container.
A) 0.75 mol SO2(g)
B) 0.25 mol of SO2 (g) and 0.25 mol of SO3 (g)
C) 1.0 mol SO3 (g)
D) 0.50 mol O2 (g) and 0.50 mol SO3 (g)
E) 0.25 mol SO2 (g) and 0.25 mol O2 (g)
5) The equilibrium-constant expression depends on the __________ of the reaction.
A) the quantities of reactants and products initially present
B) stoichiometry and mechanism
C) mechanism
D) stoichiometry
E) temperature
6) At elevated temperatures, molecular hydrogen and molecular bromine react to partially form hydrogen bromide:
H2 (g) + Br2 (g) ⇌ 2HBr (g)
A mixture of 0.682 mol of H2 and 0.440 mol of Br2 is combined in a reaction vessel with a volume of 2.00 L. At equilibrium at 700 K, there are 0.566 mol of H2 present. At equilibrium, there are __________ mol of Br2 present in the reaction vessel.
A) 0.440 B) 0.324 C) 0.000 D) 0.566 E) 0.232
7) At 200 °C, the equilibrium constant (Kp) for the reaction below is 2.40 × 103.
2NO (g) ⇌ N2