A chemical reaction is spontaneous at 298 K but non-spontaneous at 350 K. Which one of the following is true for the reaction

A chemical reaction is spontaneous at 298 K but non-spontaneous at 350

1.	A chemical reaction is spontaneous at 298 K but non-spontaneous at 350 K. Which one of the following is true for the reaction
Answer» `{:(DeltaG,DeltaH,DeltaS),("_","_","+"):}` `{:(DeltaG,DeltaH,DeltaS),("+","+","+"):}` `{:(DeltaG,DeltaH,DeltaS),("-","+","-"):}` `{:(DeltaG,DeltaH,DeltaS),("-","-","-"):}` Solution :`DeltaG=DeltaH-TDELTAS` For first condition, REACTION will be spontaneous at all temperatures. For second option as `DeltaH=+ve` and `DeltaS` is +ve THUS`DeltaG=underset(+ve)underbrace(DeltaH)-underset((-ve))underbrace(TDeltaS)` If TEMPERATURE is high, `TDeltaS` will have higher negative value and reaction will be spontaneous Thus not true for given reaction. In case (c), `DeltaG`=ve, `DeltaS=+ve` impliesspontaneous at all temperatures In case (e), `DeltaG=underset(-ve)underbrace(DeltaH)-underset(+ve)underbrace(TDeltaS)` At high temperature, second TERM will have high positive value and reaction will be non-spontaneous, thus case (e) is true for given example.