Write the equilibrium expression (K) for each of the following reactions.

A) N₂(g) + O₂(g) ⇆ 2NO(g)

B) 2NOCl(g) ⇆ 2NO(g) + Cl₂(g)

C) CH₃COOH(aq) ⇆ H⁺(aq) + CH₃COO₂^–(aq)

D) 2CuS(s) + 3O₂(g) ⇆ 2CuO(s) + 2SO₂(g)

E) CO₂(g) + 3H₂(g) ⇆ CH₃OH(g) + H₂O(g)

F) 2SO₃(g) ⇆ 2SO₂(g) + O₂(g)

G) CaCO₃(s) ⇆ CaO(s) + CO₂(g)

H) Fe₂O₃(s) + 3CO(g) ⇆ 2Fe(s) + 3CO₂(g)

I) 4HCl(g) + O₂(g) ⇆ 2Cl₂(g) + 2H₂O(g)

J) CO₃^2-(aq) + H₂O(l) ⇆ HCO₃^–(aq) + OH^–(aq)

K) P₄(s) + 5O₂(g) ⇆ P₄O₁₀(s)

l) 2H⁺(aq) + Zn(s) ⇆ H₂(g) + Zn²⁺(aq)

Tree different reactions are represented in the diagram below. The reaction equations can be written as A + X ⇆ AX (X = B, C, or D).

(a) Which reaction has the largest equilibrium constant? (b) Which reaction has the smallest equilibrium constant?

The following graph represents an initial mixture of N₂ and H₂ at high temperature and pressure:

The gases react to form ammonia gas (NH₃) as represented by the following concentration profile:

a) Label each plot on the graph as H₂, N₂, or NH₃, and explain your answers.

b) What information do the relative shapes of the plots tell us?

c) At what time is equilibrium reached?

At a particular temperature, it is determined for the reaction

2NO(g) + 2H₂(g) ⇆ N₂ (g) + 2H₂O(g)

that at equilibrium, the concentrations are as follows: [NO(g)] = 3.2 x 10^-3 M, [H₂(g)] = 6.7 x 10^-6 M, [N₂(g)] = 4.8 x 10^-2 M, and [H₂O(g)] = 2.4 x 10^-2 M. What is the value of the equilibrium constant K for the reaction at this temperature?

Given the equilibrium concentrations, calculate the value of the equilibrium constant K for the reaction between CO₂ and H₂ that produces methanol and water at high temperature.

CO₂(g) + 3H₂(g) ⇆ CH₃OH(g) + H₂O(g)

[CO₂] = 0.061 M, [H₂] = 0.079 M, [CH₃OH] = 4.7 x 10² M, and [H₂O] = 5.7 x 10⁴ M Calculate the value of K for the reaction.

The reaction for converting methane to acetylene has an equilibrium constant of K = 0.154 at 2000 K.

2CH₄(g) ⇆ C₂H₂(g) + 3H₂(g)

Calculate the equilibrium constant for this process if the reaction is represented as follows:

a) CH₄(g) ⇆ 1/2C₂H₂(g) + 3/2H₂(g)

b) 4CH₄(g) ⇆ 2C₂H₂(g) + 6H₂(g)

c) 6CH₄(g) ⇆ 3C₂H₂(g) + 9H₂(g)

The following reaction has an equilibrium constant of K_p = 4.42 x 10^-5 at 298 K:

CH₃OH(g) ⇆ CO (g) + 2H₂(g)

Calculate the equilibrium constant for this process if the reaction is represented as follows:

a) CO(g) + 2H₂(g) ⇆ CH₃OH(g)

b) 2CH₃OH(g) ⇆ 2CO(g) + 4H₂(g)

c) 1/2CH₃OH(g) ⇆ 1/2CO(g) + H₂(g)

The equilibrium constant values for the reactions below were determined at a certain temperature:

S(s) + O₂(g) ⇆ SO₂(g)    K_a = 3.2 x 10⁴⁵

2S(s) + 3O₂(g) ⇆ 2SO₃(g)    K_b = 3.2 x 10¹²⁴

Using these data, determine the equilibrium constant Kc for the following reaction:

2SO₂(g) + O₂(g) ⇆ 2SO₃(g)    K_c = ?

The equilibrium constant values for the reactions below were determined at a certain temperature:

2NO(g) ⇆ N₂(g) + O₂(g) Ka = 3.8 x 10³²

NO(g) + 1/2Cl₂(g) ⇆ NOCl(g) Kb = 6.4

Using these data, determine the equilibrium constant Kc for the following reaction:

1/2N₂(g) + 1/2O₂(g) + 1/2Cl₂(g) ⇆ NOCl(g) Kc = ?

The following equilibrium pressures were observed at a certain temperature for the Haber process

3H₂(g) + N₂(g) ⇆ 2NH₃(g)

P(NH₃) = 5.2 x 10⁹ atm

P(N₂) = 6.1 x 10² atm

P(H₂) = 4.7 x 10³ atm

Calculate the value for the equilibrium constant Kp at this temperature.

Consider the following reactions:

1) H₂(g) + I₂(g) ⇆ 2HI(g)

2) H₂(g) + I₂(s) ⇆ 2HI(g)

In which reaction are the K and Kp equal?

At 300 K, the equilibrium concentrations for the following reaction are [CH₃OH] = 0.240 M, [CO] = 0.350 M, and [H₂] = 1.65 M for the reaction

CH₃OH(g) ⇆ CO(g) + 2H₂(g)

Calculate Kp at this temperature.

Given the equilibrium constant, calculate Kp for each of the following reactions at 298 K.

a) N₂O₄(g) ⇆ 2NO₂(g) Kc = 4.6 x 10^-4

b) 3H₂(g) + N₂(g) ⇆ 2NH₃(g) Kc = 6.7 x 10⁹

c) H₂(g) + B₂(g) ⇆ 2HBr(g) Kc = 5.20 x 10¹⁸

Calculate the K_c for each reaction at 298 K.

a) CO(g) + Cl₂(g) ⇆ COCl₂(g) Kp = 5.3 x 10⁶

b) CH₄(g) + H₂O(g) ⇆ CO(g) + 3H₂(g) Kp = 7.7 x 10⁸

c) 2SO₂(g) + O₂(g) ⇆ 2SO₃(g) Kp = 6.26 x 10⁵

Consider the reaction between nitrogen and hydrogen gases:

3H₂(g) + N₂(g) ⇆ 2NH₃(g)

Using the data given in the table, complete the missing numbers assuming that all concentrations are measured at equilibrium.

Consider the following reaction at 298 K:

2NO(g) + Cl₂(g) ⇆ 2NOCl(g) Kp = 31.6

In a reaction mixture at equilibrium, the partial pressure of NO is 128 torr and that of Cl₂ is 176 torr. Calculate the partial pressure of NOCl at equilibrium.

The equilibrium constant for the following reaction at 600 ^oC is determined to be Kc = 0.495:

H₂O(g) + CO(g) ⇆ H₂(g) + CO₂(g)

Calculate the number of H₂ moles that are present at equilibrium if a mixture of 0.400 mole CO and 0.500 mole H₂O is heated to 600°C in a 10.0-L container.

The equilibrium constant Kc for the following reaction at 800°C is 3.74 x 10⁵

H₂(g) + I₂(g) ⇆ 2HI(g)

If 6.25 moles of HI were initially added to a 15.0-L empty vessel, what would the concentrations of H₂, I₂, and HI be at equilibrium.

The equilibrium constant for the following reaction at 700 K is Kp = 6.7 x 10^-3

CO(g) + 2H₂(g) ⇆ CH₃OH(g)

A reaction mixture contains 0.248 atm of H₂, 0.085 atm of CO, and 0.598 atm of CH₃OH. Is the reaction mixture at equilibrium? If not, in what direction will the reaction proceed?

For the reaction shown below, K_c = 0.654 at 600 K.

N₂O₄(g) ⇆ 2NO₂(g)

If initially, 0.0600 M of N₂O₄ are present in the reaction vessel, what are the equilibrium concentrations of the gases at 600 K?

For the reaction shown below, Kc = 255 at 800 K.

PCl₃(g) + Cl₂(g) ⇆ PCl₅(g)

If a reaction mixture initially contains 0.3500 M PCl₃ and 0.375 M Cl₂ at 800 K, what are the equilibrium concentrations of all the species in the mixture?

Consider the following reaction characterized with K_p = 2.34 x 10^-4 at 250 K:

I₂(g) + Cl₂(g) ⇆ 2ICl(g)

A reaction mixture initially contains I₂ with partial pressure of 655 torr and Cl₂ with partial pressure of 864 torr at 250 K. Calculate the equilibrium partial pressure of ICl.

Consider the following reversible reaction:

            POCl₃(g) ⇌ POCl(g) + Cl₂(g)     Kc = 0.650

The following initial amounts of reactants and products were mixed: [POCl₃] = 0.650 M, [POCl] = 0.450 M, and [Cl₂] = 0.250 M.

Calculate the reaction quotient, Q_c, and determine the equilibrium concentration of POCl?

Consider the following equilibrium:

2NO(g) + 2H₂(g) ⇆ N₂(g) + 2H₂O(g)

Initially, there are 0.15 moles of NO and 0.25 moles of H₂, in a 10.0-L container. If there are 0.056 moles of NO at equilibrium, how many moles of N₂ are present at equilibrium?

Consider the following equilibrium:

          2NOCl(g) ⇆ 2NO(g) + Cl₂(g)

2.00 mole of pure NOCl and 1.65 mole of pure Cl₂ are placed in a 1.00-L container. Calculate the equilibrium concentration of NO(g) considering that with K = 2.4 x 10^–6.

Consider the following equilibrium process

2SO₃(g) ⇆ 2SO₂(g) + O₂(g)   ΔH° = 2198 kJ/mol

How will the concentrations of SO₂, O₂, and SO₃ be affected in each scenario?

(a) the temperature is increased

(b) the pressure is decreased by increasing the volume of the container

(c) the concentration of O₂ is increased

(d) a is added catalyst

(e) an inert gas is added at constant volume

Suppose you need to increase the amount of C₃H₆Cl₂ produced in the following exothermic reaction:

C₃H₆(g) + Cl₂(g) ⇆ C₃H₆Cl₂(g)

Which of the following strategies will work once the reaction mixture reaches equilibrium?

a) decreasing the reaction volume

b) removing C₃H₆Cl₂ from the reaction mixture as it forms

c) adding a catalyst

d) adding Cl₂

e) increasing the temperature

Predict the shift in the equilibrium position that will occur for each of the following reactions at equilibrium when the volume of the reaction container is increased.

1) PCl₃(g) + Cl₂(g) ⇆ PCl₅(g)

2) 2NBr₃(g) ⇆ N₂(g) + 3Br₂(g)

3) CO(g) + Cl₂(g) ⇆ COCl₂(g)

4) H₂(g) + B₂(g) ⇆ 2HBr(g)

5) MgCO₃(s) ⇆ MgO(s) + CO₂(g)

Consider the following equilibrium process for the commercial production of hydrogen:

CO(g) + H₂O(g) ⇆ CO₂(g) + H₂(g)    ΔH° = +42 kJ/mol

Predict the direction of the shift in equilibrium when

(a) the temperature is raised.

(b) more CO gas is added to the reaction mixture.

(c) some CO₂ is removed from the mixture.

(d) the pressure on the gases is increased by changing the volume of the container.

(e) a catalyst is added to the reaction mixture

Consider this reaction at equilibrium:

N₂ + O₂(g) ⇆ 2NO(g)

Predict whether the reaction will shift left, shift right, or remain unchanged after each disturbance.

a) NO is added to the reaction mixture.

b) N₂ is added to the reaction mixture.

c) NO is removed from the reaction mixture.