10-minute Quiz : Chapter 40 Equilibrium constant

Given that the equilibrium constant for Reaction I has a numerical value of 4.0 at a certain temperature. What is the numerical value of the equilibrium constant for Reaction II at the same temperature?

• A. 0.25
• B. 0.063
• C. 2.0
• D. 8.0

Given that the equilibrium constant for the following reaction is 0.25 at 440°C.

2HI(g) ⇌ H₂(g) + I₂(g)

What is the equilibrium constant for the reaction shown in the diagram at the same temperature?

• A. 0.25
• B. 0.50
• C. 1.00
• D. 2.00

Consider the following reversible reaction:

2SO₂(g) + O₂(g) ⇌ 2SO₃(g)

In an experiment, 0.060 mol dm⁻³ of SO₂(g) and 0.050 mol dm⁻³ of O₂(g) were introduced into a vessel with a fixed volume kept at a certain temperature. When equilibrium was attained, the system had 0.040 mol dm⁻³ of SO₃(g). What was the equilibrium concentration of O₂(g)?

• A. 0.010 mol dm⁻³
• B. 0.020 mol dm⁻³
• C. 0.030 mol dm⁻³
• D. 0.040 mol dm⁻³

Nitrosyl chloride dissociates reversibly to form nitrogen oxide and chlorine according to the equation shown in the diagram. In an experiment, 1.50 g of a sample of nitrosyl chloride was heated at 350°C in a 1.00 dm³ vessel. The percentage of dissociation of the nitrosyl chloride was found to be 57.2%. What was the equilibrium constant for this reaction at that temperature?

(Relative atomic masses: N = 14.0, O = 16.0, Cl = 35.5)

• A
• B
• C
• D

Consider the reversible reaction shown in the diagram. What is the equilibrium concentration of NO(g) when the initial concentration of N₂(g) and O₂(g) in this gaseous system are both 0.040 mol dm⁻³?

• A. 0.011 mol dm⁻³
• B. 0.080 mol dm⁻³
• C. 0.0055 mol dm⁻³
• D. 0.0096 mol dm⁻³

Consider the following reaction which takes place in a 1.00 dm³ vessel at 200°C.

X(g) + Y(g) ⇌ 2Z(g)

Given that the equilibrium concentrations of X(g), Y(g) and Z(g) are 0.200 mol dm⁻³, 3.00 mol dm⁻³ and 0.500 mol dm⁻³ respectively. How many additional moles of X(g) should be added to further increase the concentration of Z(g) to 0.700 mol dm⁻³ at the same temperature?

• A. 0.225 mol
• B. 0.305 mol
• C. 0.417 mol
• D. 0.610 mol

Consider the following three equilibrium systems, each taking place at certain conditions:

System I: PCl₅(g) ⇌ PCl₃(g) + Cl₂(g)

System II: 2HI(g) ⇌ H₂(g) + I₂(g)

System III: N₂(g) + 3H₂(g) ⇌ 2NH₃(g)

Assuming the equilibrium concentration of every species in each system above is 0.01 M, which of the following arranges the extent of these reactions in the correct order?

• A. I < II < III
• B. I > II > III
• C. II > III > I
• D. III > I > II

The equilibrium constants for the following reactions, each taking place at the same temperature, are K₁ and K₂ respectively.

Reaction I: 2P(g) + 3Cl₂(g) ⇌ 2PCl₃(g)　　K₁

Reaction II: PCl₃(g) + Cl₂(g) ⇌ PCl₅(g)　　K₂

What is the equilibrium constant for the following reaction at the same temperature?

2P(g) + 5Cl₂(g) ⇌ 2PCl₅(g)

• A. K₁ + 2K₂

• B. K₁ + K₂²

• C. K₁²K₂

• D. K₁K₂²

Direction: Questions 9 and 10 refer to the concentration-time graph, which shows the variation of the concentrations of three gases, X(g), Y(g) and Z(g), in a reversible reaction at a given temperature.

Which of the following equations correctly represents this gaseous reaction?

• A. X(g) + Y(g) ⇌ Z(g)

• B. X(g) + Y(g) ⇌ 2Z(g)

• C. 2X(g) + Y(g) ⇌ 2Z(g)

• D. 2X(g) + Y(g) ⇌ Z(g)

Direction: Questions 9 and 10 refer to the concentration-time graph, which shows the variation of the concentrations of three gases, X(g), Y(g) and Z(g), in a reversible reaction at a given temperature.

What is the equilibrium constant for this gaseous reaction at that given temperature?

• A. 0.8
• B. 1.4
• C. 2.0
• D. 2.7