Write a relation between G and Q and define the meaning of each term and answer the following.

1.  Why a reaction proceeds forward when Q

2.  Explain the effect of increase in pressure in terms of reaction quotient Q. For the reaction, CO(g)+3H2(g)CH4(g)+H2O(g)

The relation between G and Q is
G=G+RTlnQG=change in free energy as the reaction proceeds.G=standard free energyQ=reaction quotientR=gas constantT=absolute temperature in K
(a) G=-RT ln K
G=-RT ln K+RT ln QG=RT ln QK
If Q < K, G will be negative and the reaction proceeds in the forward reaction.
If Q = K, G=0 reaction is in equilibrium and there is no net reaction.
(b) CO(g)+3H2(g)CH4(g)+H2O(g)
On increasing pressure, volume decreases. If we doubled the pressure, volume will be halved but the molar concentrations will be doubled. Then,
Therefore, Qc is less than Kc, so Qc will tend to increase to re-establish equilibrium and the reaction will go in forward direction.