The Equilibrium Constant Practice Problems

Solid sodium bicarbonate is converted to solid sodium carbonate, carbon dioxide gas, and water vapor only when sufficiently heated. At equilibrium, the reaction has a K value of 1.59 × 10⁻⁶ at 25 °C. 

2 NaHCO₃ (s) ⇌ Na₂CO₃ (s) + CO₂ (g) + H₂O (g)

Determine whether the formation of the reactant or the products is favored. 

Consider the following equilibrium (K_c = 2.68 × 10⁻³ at 800 °C):

CaCO₃ (s) ⇌ CaO (s) + CO₂ (g)

Is the formation of products favored at equilibrium? What is/are the relative concentration/s of the species involved at equilibrium?

The following conversion has an equilibrium constant (K_c) of 1.1 × 10⁻³ at 1280 °C.

Br₂ (g) ⇌ 2 Br (g)

Determine whether the reactant or the product is favored at equilibrium. 

Consider the equilibrium process (K = 34 at 25 °C):

Lactose (aq) + H₂O (l) ⇌ Glucose (aq) + Galactose (aq) 

Is the formation of products favored at equilibrium? What are the relative concentrations of the species involved at equilibrium?

Consider the equilibrium reaction: 

H₂ (g) + I₂ (g) ⇌ 2 HI (g)

Calculate [I₂] at equilibrium when [H₂] = 0.0160 mol/L and [HI] = 0.0320 mol/L (K = 2.90×10⁻¹ at 300 Kelvin). 

Consider the equilibrium reaction: 

F₂ (g) ⇌ 2 F (g);  K = 7.40×10⁻¹³ at 500 Kelvin

Calculate [F₂] at equilibrium when [F] = 5.25×10⁻⁴ mol/L.

Phosphoryl chloride is formed by the reaction of phosphorus trichloride with oxygen: PCl₃(g) + O₂(g) ⇌ POCl₃(g).

Provide the equilibrium expression.

Provide the equilibrium expression for: CH₄(g) + 2 H₂S(g) ⇌ CS₂(g) + 4 H₂(g)

Provide the equilibrium expression for: NH₄NO₃(s) ⇌ N₂O(g) + 2 H₂O(g)

Consider the equilibrium reaction shown in the image below:

Calculate the value of K for the reaction.

Consider the reaction A + B₂ + 2 C ⇌ 3 D at equilibrium. Provide the equilibrium expression for the reaction.

Which of the following statements is true for a chemical reaction for which the value of equilibrium constant (K) is too large (K >> 1)?

Write the equilibrium constant expression for the following reaction:

CaCO₃(s) ⇌ CaO(s) + CO₂(g)

Consider the following reaction at 298 K:

A(g) + 3 B₂(g) → 2 C(g)

At equilibrium partial pressures are A = 0.075 atm, B₂ = 0.58 atm, and C = 0.753 atm. What is the value of K_p?