Equilibrium Constant and Standard Free Energy Change
The equilibri...
Question
The equilibrium constant for the reaction given below is 2.0×10−7 at 300 K. Calculate the standard free energy change for the reaction. PCl5(g)⇌PCl3(g)+Cl2(g)
Also, calculate the standard entropy change if, ΔH∘=28.40kJmol−1
A
38.48kJ,−33.6Jmol−1K−1
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
B
48.48kJ,−33.6Jmol−1K−1
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
38.48kJ,−43.6Jmol−1K−1
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
48.48kJ,−43.6Jmol−1K−1
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution
The correct option is A38.48kJ,−33.6Jmol−1K−1 K=2.0×10−7T=300KΔH∘=28.4kJmol−1ΔG∘=−2.303RTlogK=−2.303×8314×10−3×300×log(2×10−7)=−5.744(log2−7)=−5.744(0.3010−7)=38.48kJ
From ΔG∘=ΔH∘−TΔS∘⇒TΔS∘=ΔH∘−ΔG∘ΔS∘=ΔH∘−ΔG∘T=28.4−38.48300=−0.0336kJmol−1orΔS=−33.6Jmol−1K−1