JEE Main2017ChemistryThermodynamics (C)Actual
For a reaction, A g → A l ; ΔH = - 3 RT . The correct statement for the reaction is
Options
- AΔH = ΔU = O
- BΔH < ΔU
- CΔH > ΔU
- DΔH = ΔU ≠ O
Correct answer
C. ΔH > ΔU
Step-by-step solution
∆   H = ∆   U + ∆ n g RT ∆   n g = n p - n r = 0 - 1 = - 1 ∆   H = ∆   U + - 1 RT ∆   H = ∆   U - RT Given, ∆ H = - 3 RT - 3 RT =   ∆   U + - 1 RT ∆   U = - 3 RT + RT = - 2 RT ∆   H > ∆   U