Question

2. What is the value of the equilibrium constant for 298 K dissociation reaction of phosgene? The products are molecular chlorine and carbon monoxide.

Answer 1

Dissociation reaction of phosgene is as follows:

COCl2(G) = -206.77328 kj/ mole

CO (g) = -137.27704 kj/ mole

Cl2 (g) = -0 kj/ mole

COCI2(g) ------ > CO(g)+CI2(g)

dG of reaction = dG product – dG reactants

= -137.27704 kj/ mole – (-206.77328 kj/ mole)

=69.49624 KJ/ mole

Equilibrium constant can be calculated as follows:

ΔG°=−RTlnK

Here R = 8.314 J/K)

K = e^ − ΔG° /RT

= e^ 69.49624 KJ/ mole *1000 J /1.0 KJ/ 8.314 J/K *298 K

= e^- 28.05

= 6.6*10^-13