Question

the equilibrium NH4HS =NH3 +h2s is followed to set up at 127 degree Celsius in a closed vessel the total pressure at equilibrium was 20 atm the kc for the reaction is

Answer 1

To work out the Kc of this reaction all you need to do is to get the mole fraction of the each of the reactants and products in the reaction.

The mole fraction of NH4HS is 1/3

The mole fraction of NH3 is 1/3

the mole fraction of H2S is 1/3

hence find the equilibrium vapour pressure with respect to each of the reactants and the products;

Vapour pressure of NH4HS =1/3 x 20= 6.67atm

vapour pressure of NH3 = 1/3 x 20 = 6.67 atm

Vapour pressure of H2S = 1/3 x 20= 6.67 atm

Kc= [NH3] [H2S] / [NH4HS]

Kc= 6.67 x 6.67 / 6.67

Kc= 6.67.