Question

At a given temperature, 2.6 atm of h2 and 3.14 atm of cl2 are mixed and allowed to come to equilibrium. the equilibrium pressure of hcl is found to be 1.13 atm. calculate kp for the reaction at this temperature.

Answer 1

The solution would be like this for this specific problem:

Given:

H2 = 2.6 atm
CL2 = 3.14 atm

pressure H2 = 2.6 - x
pressure Cl2 = 3.14 - x
pressure HBr = 2x = 1.13

x = 1.13 / 2 = 0.565

pressure H2 = 2.6 - 0.565 = 2.035
pressure Br2 = 3.14 - 0.565 = 2.575

Kp = (1.13)^2 / 2.035 x 2.575

= 1.2769 / (5.240125)

= 0.24367739319195629875241525726963

= 0.244

Therefore, the Kp for the reaction at the given temperature is 0.244.

To add, the hypothetical pressure of a gas if it alone occupied the whole volume of the original mixture at the same temperature is called the partial pressure or Kp.