Question

Consider the following reaction:
SO2Cl2(g)⇌SO2(g)+Cl2(g)
A reaction mixture is made containing an initial [SO2Cl2] of 2.2×10⁻² M . At equilibrium, [Cl2]=1.0×10⁻² M .

Calculate the value of the equilibrium constant (Kc).

Express your answer using two significant figures.

Answer 1

Given reaction is:

SO2Cl2(g)⇌SO2(g)+Cl2(g)

Initially

[SO2Cl2] = 2.2×10⁻² M

At equilibrium,

[Cl2]=1.0×10⁻² M.

ICE

SO2Cl2(g)⇌      SO2(g)       +        Cl2(g)

I           2.2E-2             0                                  0

C         -x                     +x                                +x

E        (2.2E-2-x)          x                                 x = 1.0 E-2

Lets find all the concentrations at equilibrium

[SO2Cl2] =[ 2.2×10⁻² – 1.0 E-2 ] M = 1.2 E-2 M

[SO2]= 1.0 E-2

Kc = [SO2][Cl2]/[SO2Cl2]

Kc = (1.0E-2)² / (1.2E-2)

=0.0083

Kc = 8.3E-3