NTA Abhyas JEE Main2020ChemistryThermodynamics (C)Practice
Which one of the following options is correct for the spontaneity of the reaction?
Options
- A∆ G = positive (+Ve); ∆ H = positive (+Ve)
- B∆ H = positive (+ve); ∆ S = negative (-Ve)
- C∆ G = negative (-Ve); ∆ S = negative (-Ve)
- D∆ G = negative (-Ve); ∆ S = positive (+Ve)
Correct answer
D. ∆ G = negative (-Ve); ∆ S = positive (+Ve)
Step-by-step solution
∆ G = ∆ H - T ∆ S Where, ∆ G = Gibbs free energy change ∆ H = Enthalpy change T = Temperature in k and ∆ S = Entropy change A reaction is spontaneous, when ∆ G is negative. If ∆ S is positive, T ∆ S become positive, so that ∆ H - T ∆ S can become negative.