The correct relationship between free energy change in a reaction and the corresponding equilibrium constant `K_(c)` is:

Options

A. `DeltaG^(@)=-RT ` In K
B. `DeltaG=RT `In K
C. `DeltaG^(@)=RT` In K
D. `DeltaG^(@)=-RT` In K

Answer

A

Explanation

The Gibbs free energy of a reaction, `Delta_(I)G` is related ot the compoistion of the reaction mixture and the standard reaction Gibbs free energy `Delta_(I)G^(@)` as
`Delta_(I)G=Delta_(I)G^(@) + RT "In" Q`
where , Q=reaction quotient
At equilibrium Q=K and `Delta_(I)G=0` ,
Therefore, the above reaction becomes
`0=Delta_(I)G^(@)=-RT "In " K`
`Delta_(I)G^(@)=-RT "In " K`
or `Delta_(I)G^(@)=-2.303 RT "log" K`
K=equilibrium constant