Initially, a closed flask contains a mixture of N2 at a partial pressure of 3 atm and H2 at a partial pressure of 5 atm. The mixture reaches equilibrium and the partial pressure of NH3 is 2 atm. What is the value of the equilibrium constant?

The answer to the question is

The value of the equilibrium constant = 2.16×10⁻¹

Explanation:

To solve the question we write out the equation as follows

N₂ (g)+ H₂ (g) → 2NH₃ (g)

Given that

Partial pressure of N₂ (g), PN₂ = 3 atm

Partial pressure of H₂ (g) PH₂= 5 atm

and Partial pressure of NH₃ (g), PNH₃ = 2 atm

Given the partial pressures of the reacting gases at equilibrium such that the partial pressure of N₂ is given by PN₂ and the partial pressure of H₂ is given by PH₂ while the partial pressure of NH₃ is given by PNH₃  the expression for equilibrium constant in terms of partial pressure kp can be written as

  Hence we have

Kp = 2²/(5×3) = 2.16×10⁻¹  

Therefore the equilibrium constant = 2.16×10⁻¹