Module 3

The reaction shown below has a K_c value of 1.5 × 10⁻⁴. When this reaction reaches equilibrium, will the concentration of the reactants or products be greater?

A(g) + B(g) ⇋ 2 C(g)

Which of the following reactions represents a homogeneous equilibrium? Select all that apply.

The concentration of a pure liquid or solid does not change. What is the molar concentration of pure water to 3 significant figures?

Using the following data, find the value of K_c for the reaction below at 298 K.

2 H₂(g) + S₂(g) ⇋ 2 H₂S(g)

• H₂S(g), ΔG°_f = −33.4 kJ/mol
• S₂(g), ΔG°_f = 79.7 kJ/mol

Which of the following statements is true?

Coal, which is essentially pure carbon, can be used to generate hydrogen gas by the endothermic reaction shown below.

C(s) + H₂O(g) ⇋ CO(g) + H₂(g)

If this reaction is at equilibrium, an increase in pressure will

If the reaction shown below is at equilibrium, what effect will a decrease in pressure have on the position of the equilibrium?

I₂(g) + Cl₂(g) ⇋ 2 ICl(g)

The ΔH°_rxn for the reaction shown below is −2217 kJ.

If the reaction is allowed to come to equilibrium, what effect will an increase in temperature have on the equilibrium?

For the following reaction at equilibrium, decreasing the volume of the reaction will have what effect on the equilibrium.

If NaOH(aq) were added to the following reaction at equilibrium, in which direction would the reaction shift?

H₂(aq) + Cl₂(aq) ⇋ 2 HCl(aq)

Consider the reaction shown below.

A(aq) + B(aq) ⇋ C(aq) +D(aq)

Which of the following perturbations would cause more C(aq) to form? Select all that apply.

CHALLENGING: Pure N₂O₄(g) was added to an empty, closed flask at 127 °C until the pressure reached 4.38 × 10^-2 atm. The system was allowed to come to equilibrium according to the following equation.

At equilibrium, the total pressure in the flask was 7.43 × 10^-2 atm. What is the value of K_p for this reaction?

The value of K_P for the reaction shown below is 1.1 × 10⁻⁴ at 150 K. What is the value of K_C at this temperature?

Consider the following reactions and their values for Kc.

S(s) + O₂(g) ⇋ SO₂(g)     K_c = 4.2 × 10⁵²

2 S(s) + 3 O₂(g) ⇋ 2 SO₃(g)     K_c = 9.8 × 10¹²⁸

Consider the following reaction.

N₂(g) + O₂(g) ⇋ 2 NO(g)

At 2200 °C, the value of K for this reaction is 0.051. If the reaction initially has the following concentrations, in which direction will the reaction shift to reach equilibrium? [NO] = 0.060 M, [N₂] = 0.11 M, and [O₂] = 0.30 M.