MEDIUMMCQ SINGLEIChO (Chemistry Olympiad)Physical ChemistryThermodynamics and ThermochemistryPrevious Year Questions
The correct thermodynamic conditions for the spontaneous reaction at all temperatures is (NEET-I 2016)
A.∆H < 0 and ∆S > 0 (b) ∆H < 0 and ∆S < 0✓ Correct
C.∆H < 0 and ∆S = 0 (d) ∆H > 0 and ∆S < 0
Explanation
∆G = ∆H – T∆S If ∆H < 0 and ∆S > 0 ∆G = (–ve) – T(+ve) then at all temperatures, ∆G = –ve, spontaneous reaction. If ∆H < 0 and ∆S = 0 ∆G = (–ve) – T(0) = –ve at all temperatures.