The equilibrium pressures below were observed at a certain temperature for the following reaction.

PNH₃ = 3.1 ✕ 10⁻² atm
PN₂ = 8.5 ✕ 10⁻¹ atm
PH₂ = 3.1 ✕ 10⁻³ atm
Calculate the value for the equilibrium constant at this temperature.

37 950

Explanation:

Thinking process:

Let's consider a reversible gaseous reaction:

As all the reactants and products are gaseous, the reaction is a homogeneous reaction. In other words, the reactants and and products are in the same phase.

The equilibrium constant is expressed in terms of partial pressures like this:

using the formula for the reaction in the question:

Kp = (3.1 ✕ 10⁻² atm)²/ (8.5 ✕ 10⁻¹ atm) (3.1 ✕ 10⁻³ atm)³

     = 37 950