Equilibrium Equations

A 0.10 mol sample of each of the four species in the reaction represented above is injected into a rigid, previously evacuated 1.0 L container. Which of the following species will have the highest concentration when the system reaches equilibrium?

• H₂S _(g)

• CH_{4 (g)}

• CS_{2 (g)}

• H_{2 (g)}

2 S_(s) + 2 O_2(g) ⇄ 2 SO_2(g) K₁ = 2 x 10¹⁰⁵

2 SO_2(g) + O_2(g) ⇄ 2 SO_3(g) K₂ = 7 x 10²⁴

Given the value of the equilibrium constants K₁ and K₂ for the reactions represented above, what is the value of the equilibrium constant, K₃, for the following reaction?

2 S_(s) + 3 O_2(g) ⇄ 2 SO_3(g) K₃ = ?

• 1 x 10¹³⁰

• 3 x 10⁸⁰

• 1 x 10⁶⁵

• 2 x 10⁴⁰

• 7 x 10²⁴

Tags

NGSS.HS-PS1-7

2 XY_(g) ⇄ X_2(g) + Y_2(g) K_p = 230

A certain gas, XY_(g), decomposes as represented by the equation above. A sample of each of the three gases is put in a previously evacuated container. The initial partial pressures of the gases are shown in the table.

The temperature of the reaction mixture is held constant. In which direction will the reaction proceed?

• The reaction will form more products.

• The reaction will form more reactant.

• The mixture is at equilibrium, so there will be no change.

• It cannot be determined unless the volume of the container is known.

Tags

NGSS.HS-PS1-5

2X_(g) + Y_(g) ⇄ 3Z_(g)

The reaction mixture represented above is at equilibrium at 298 K, and the molar concentrations are [X] = 2.0 M, [Y] = 0.5 M, and [Z] = 4.0 M. What is the value of the equilibrium constant for the reaction at 298 K ?

• 0.50

• 2.0

• 4.0

• 16

• 32

3 O_2(g) ⇄ 2O_3(g) K_c = 1.8 × 10⁻⁵⁶ at 570 K

For the system represented above, [O₂] and [O₃] initially are 0.150 mol/L and 2.5 mol/L respectively. Which of the following best predicts what will occur as the system approaches equilibrium at 570 K?

• The amount of O_3(g) will increase, because Q < K_c.

• The amount of O_3(g) will decrease, because Q < K_c.

• The amount of O_3(g) will increase, because Q > K_c.

• The amount of O_3(g) will decrease, because Q > K_c.

Tags

NGSS.HS-PS1-5

A 2.0 mol sample of CO_(g) and a 2.0 mol sample of H₂O_(g) are introduced into a previously evacuated 100. L rigid container, and the temperature is held constant as the reaction represented above reaches equilibrium. Which of the following is true at equilibrium?

• [H₂O] > [CO] and [CO₂] > [H₂]

• [H₂O] > [H₂]

• [CO₂] > [CO]

• [CO] = [H₂O] = [CO₂] = [H₂]

Tags

NGSS.HS-PS1-5

NGSS.HS-PS1-7

CO_(g) + 2 H_2(g) ⇄ CH₃OH_(g) ΔH < 0

The synthesis of CH₃OH_(g) from CO_(g) and H_2(g) is represented by the equation above. The value

of K_c for the reaction at 483 K is 14.5.

A 1.0 mol sample of CO_(g) and a 1.0 mol sample of H_2(g) are pumped into a rigid, previously evacuated 2.0 L reaction vessel at 483 K. Which of the following is true at equilibrium?

• [H₂] = 2[CO]

• [H₂] < [CO]

• [CO] = [CH₃OH] < [H₂]

• [CO] = [CH₃OH] = [H₂]

Tags

NGSS.HS-PS1-2

NGSS.HS-PS1-7

COCl_2(g) ⇄ CO_(g) + Cl_2(g)

COCl_2(g) decomposes according to the equation above. When pure COCl_2(g) is injected into a rigid, previously evacuated flask at 690 K, the pressure in the flask is initially 1.0 atm. After the reaction reaches equilibrium at 690 K, the total pressure in the flask is 1.2 atm. What is the value of K_p for the reaction at 690 K?

• 0.040

• 0.050

• 0.80

• 1.0

The equilibrium reaction between Cl_{2 (aq)} and H₂O _(l) at 25 ^oC is represented by the chemical equation shown above. If a solution at equilibrium at 25 ^oC is diluter with distilled water to twice its original volume, which of the following gives the value for Q and predicts the response by the system immediately after dilution?

• Q = 4 K, and the rate of the reverse reaction will be greater than the rate of the forward reaction.

• Q = 4 K, and the rate of the forward reaction will be greater than the rate of the reverse reaction.

• Q = K/4, and the rate of the reverse reaction will be greater than the rate of the forward reaction.

• Q = K/4, and the rate of the forward reaction will be greater than the rate of the reverse reaction.

Tags

NGSS.HS-PS1-5

2 NO_(g) + Cl_2(g) ↔ 2 NOCl_(g) K = 2000

A mixture of NO_(g) and Cl_{2 (g)} is placed in a previously evacuated container and allowed to reach equilibrium according to the chemical equation shown above. When the system reaches equilibrium, the reactants and products have the concentrations listed in the table. Which of the following is true if the volume of the container is decreased by one half?

• Q = 100, and the reaction will proceed toward reactants.

• Q = 100, and the reaction will proceed toward products.

• Q = 1000, and the reaction will proceed toward reactants.

• Q = 1000, and the reaction will proceed toward products.

Tags

NGSS.HS-PS1-5