The correct option is B -5.744
We know that, the relation of Gibbs free energy and equilibrium constant at equilibrium conditions is given by ΔGo=−2.303 RT log Kc
Given,
T=300 K
Kc=10
R=8.314 J mol−1 K−1
Substituting the values we get,
ΔGo=−2.303×8.314×300×log 10
ΔGo=−5744.14×log 10
ΔGo=−5744.14 J/mol (∵log 10=1)
ΔGo=−5.744 kJ/mol
Theory:
Consider for the given reaction:
aA(aq)+bB(aq)⇌cC(aq)+dD(aq)
Gibbs free energy change is given by: ΔG=ΔG∘+RT ln Q
Where, Q= ReactionQuotient
ΔG=ΔG∘+2.303.RT log10Q
Where, ΔG∘ is standard Gibbs free energy change
At equilibrium, ΔG=0 and Q=Kc
ΔG∘=−2.303 RT log10Kc
ΔG∘=−RT ln Kc