For a gaseous reaction standard conditions are 298 K and a p

For a gaseous reaction, standard conditions are 298 K and a partial pressure of 1 atm for all species. For the reaction C2H6 (g)+ H2 (g) -> 2CH4

the standard change in Gibbs free energy is ?G

Solution

Kp= pCH4/(pC2H6*pH2)

=0.75/(0.15*0.15)

=0.0225

Kp = Kc* (RT)^n

here n=0

So Kp= Kc=0.0225

delta G= -RT lnKc

=-8.314*298* ln(0.0225)= +9.4 kJ/mol