he total entropy change for a t process is where AS, and AS ur are the entropy p
ID: 580331 • Letter: H
Question
he total entropy change for a t process is where AS, and AS ur are the entropy pontaneous process asuw> 0 For a process at constant P ard T, we can use an alternative criter on based on the Gibbs ree energy o-HTS ofthe system changes in the system and the surroundings, respectively. For a reversible process, AS -O, whereas for an irreversible or G-AH-TAS sO (constant P and T That is, aG- for a reversible, cquilibrium process, and AG Ko for an irmeversible or spontancous process. Is the following statement true or fal P and T is always spontancous. An exothermic process at constant OTruc O FalseExplanation / Answer
False.
An exothermic reaction has delta H negative.
But for the spontaneity of reaction Delta G should be negative .
That is
Delta G = delta H - T.delta S
Delta H is negative for exothermic reaction. If delta S is positive then the reaction is spontaneous at all temperatures as both the terms are negative , making delta G always negative.
However if delta S is also negative, that is the second term Tdelta S is positive. Then at higher temperatures T.delta S > delta H and then delta G is positive. Then the reaction is non-spontaneous at high temperatures.
The enthalpy is not the only criterion of spontaneity , but also entropy.
Both together decide the spontaneity.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.