Consider the reaction A leftharpoons B at 1000 K. At time 't', the temperature of the system was increased to 2000 K and the system was allowed to reach equilibrium. Throughout this experiment the partial pressure of A was maintained at 1 bar. Given below is the plot of the partial pressure of B with time. What is the ratio of the standard Gibbs energy of the reaction at 1000 K to that at 2000 K ?

Question

Consider the reaction A leftharpoons B at 1000 K. At time 't', the temperature of the system was increased to 2000 K and the system was allowed to reach equilibrium. Throughout this experiment the partial pressure of A was maintained at 1 bar. Given below is the plot of the partial pressure of B with time. What is the ratio of the standard Gibbs energy of the reaction at 1000 K to that at 2000 K ? (A)  (B)  (C)  (D)

Tardigrade Admin · Accepted Answer

K 1 at 1000 K =(10/1)=10 K 2 at 2000 K =(100/1)=100 Δ G 1°=- RT 1 ln 10=-2.303 RT 1 Δ G 2°=-2.303 RT 2 log 100 =-2 × 2.303 RT 2 (Δ G 1°/Δ G 2°)=(1 × 1000/2 × 2000)=(1/4)=0.25

K1​ at 1000K=110​=10 K2​ at 2000K=1100​=100 ΔG1∘​=−RT1​ln10=−2.303RT1​ ΔG2∘​=−2.303RT2​log100 =−2×2.303RT2​ ΔG2∘​ΔG1∘​​=2×20001×1000​=41​=0.25