Question

What is the equilibrium constant K_eq for the following reaction at 400K.

2NOCl_(g) ⇌ 2NO_(g) + Cl_2(g) given that AH° = 77.2 kJ mol^-1 and ∆S° = 122 JK^-1 mol^-1

Answer 1

T = 400 K ; ∆H° = 77.2 kJ mol^-1 = 77200 J mol^-1 ; 

∆S° = 122 JK^-1 mol^-1 

∆G° = -2.303 RT log K_eq

log K_eq = -3.7080

K_eq = anti log(-3.7080) 

K_eq = 1.95 x 10^-4