NTA Abhyas JEE Main2020ChemistryThermodynamics (C)Practice
Enthalpy is equal to
Options
- AT 2 ∂ G / T ∂ T P
- B– T 2 ∂ G / T ∂ T P
- CT 2 ∂ G / T ∂ T V
- D– T 2 ∂ G / T ∂ T V
Correct answer
B. – T 2 ∂ G / T ∂ T P
Step-by-step solution
G = H – T S …(i) G = U + P V – T S Δ G = Δ U + P Δ V + V Δ P - T Δ S - S Δ T From the first and second laws, T Δ S = Δ U + P Δ V Δ G = V Δ P - S Δ T At constant pressure, Δ P = 0 Δ G Δ T = – S …(ii) From equations. (i) and (ii) G = H + T Δ G Δ T or G = H + T ∂ G ∂ T P - H T 2 = - G T 2 + 1 T ∂ G ∂ T P = ∂ G / T ∂ T P H = - T 2 ∂ G / T ∂ T P