Q.

Dissociation of a gas A2 takes place according to the following chemical reaction.  At equilibrium, the total pressure is 1 bar at 300K.

A2(g)2A(g)

The standard Gibbs energy of formation of the involved substances has been provided below:

Substance ΔGf°/kJ mol-1
A2 - 100.00
A - 50.832

The degree of dissociation of A2(g) is given by (x×10-2)1/2 where x =_______. (Nearest integer).

[Given: R=8 J mol-1K-1,  log2=0.3010,  log3=0.48]

Assume degree of dissociation is not negligible.                                       [2026]


Ans.

(33)

-1.664×103=-8.3×300lnKp

lnKp=0.693

Kp=2

2=4α2P01-α2

α=13

α=(1003×10-2)1/2

=(33.33×10-2)1/2