DeltaG is net energy available to do useful work and is thus a measure of "free energy " . Show mathematically that DeltaG is a meausre of free energy. Find the unit ofDeltaG. Ifa reaction has positive enthalpy change and positive entropy change, under what condition will condition will the reaction be spontaneous ?

DeltaG is net energy available to do useful work and is thus a measure

1.	DeltaG is net energy available to do useful work and is thus a measure of "free energy " . Show mathematically that DeltaG is a meausre of free energy. Find the unit ofDeltaG. Ifa reaction has positive enthalpy change and positive entropy change, under what condition will condition will the reaction be spontaneous ?
Answer» Solution :(i) Referto art (ii)As - `DeltaG = w_("useful"), ` THEREFORE, `DeltaG` has the same units those of work viz. JOULE. (III) `DeltaG = DeltaH- T DeltaS`. If `DeltaH = +ve` and` DeltaS = +ve` , then `DeltaG` will be negative, i.e., process will be spontaneous only when `T DeltaS GT DeltaH`in magnitude , which will be so when temperature T is high.