Consider the following reversible reaction, A(g) + B(g) leftharpoons AB(g). The activation energy of the backward reaction exceeds that of the forward reaction by 2RT (in J mol−1). If the pre-exponential factor of the forward reaction is 4 times that of the reverse reaction, the absolute value of ΔGƟ (in J mol−1) for the reaction at 300 K is . (Given; ln(2) = 0.7, RT = 2500 J mol−1 at 300 K and G is the Gibbs energy)

Question

Consider the following reversible reaction, A(g) + B(g) leftharpoons AB(g). The activation energy of the backward reaction exceeds that of the forward reaction by 2RT (in J mol−1). If the pre-exponential factor of the forward reaction is 4 times that of the reverse reaction, the absolute value of ΔGƟ (in J mol−1) for the reaction at 300 K is . (Given; ln(2) = 0.7, RT = 2500 J mol−1 at 300 K and G is the Gibbs energy) (A)  (B)  (C)  (D)

Tardigrade Admin · Accepted Answer

A(g)+B(g) leftharpoons A B(g) Ea b-Ea f=2 R T ⇒ Δ H=-2 R T and (Af/Ab)= Ke q=((Kf/Kb))=(Af e-E af R T/Ab e-E ab / R T)=4(e2) Δ G°=-R T ln K=-2500 × ln (4 × e2) =-8500 J / mol

A(g)​+B(g)​⇌AB(g)​ Eab​−Eaf​=2RT ⇒ΔH=−2RT and Ab​Af​​= Keq​=(Kb​Kf​​)=Ab​e−Eab​/RTAf​e−Eaf​RT​=4(e2) ΔG∘=−RTlnK=−2500×ln(4×e2) =−8500J/mol