Question

1.72 moles of NOCI were placed in a 2.50 L reaction chamber

at 427°C. After equilibrium was reached, 1.16 moles of NOCI
remained. Calculate the equilibrium constant, K., for the
reaction
2NOCI(g) = 2NO(g) + Cl2(g).

Answer 1

The equilibrium constant, Kc=0.026

Further explanation

Given

1.72 moles of NOCI

1.16 moles of NOCI remained

2.50 L reaction chamber

Reaction

2NOCI(g) = 2NO(g) + Cl2(g).

Required

the equilibrium constant, Kc

Solution

ICE method

2NOCI(g) = 2NO(g) + Cl2(g).

I 1.72

C 0.56 0.56 0.28

E 1.16 0.56 0.28

Molarity at equilibrium :

NOCl :

`\tt (1.16)/(2.5)=0.464`

NO :

`\tt (0.56)/(2.5)=0.224`

Cl2 :

`\tt (0.28)/(2.5)=0.112`

`\tt Kc=([NO]^2[Cl_2])/([NOCl]^2)\\\\Kc=(0.224^2* 0.112)/(0.464^2)=0.026`