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 dekta G
Solution
delta G=delta G0+RTlnK=delta G0+8.314*298*ln(0.75^2/0.15^2)
=-69+7.98
=-61.02KJ/mole

