For the reaction at 298 K : 2A +B `to` C
`DeltaH="400 KJ mol"^(-1) , DeltaS ="0.2 JK"^(-1) "mol"^(-1)`
Determine the temperature at which the reaction would be spontaneous .

Explanation

Given: T=298 K
`DeltaH=400 "J mol"^(-1) =400 "J mol"^(-1)`
`DeltaS=0.2 JK^(-1) mol^(-1)`
`DeltaG=DeltaH-TDeltaS`
If T=2000 K
`DeltaG`=400 -(0.2 x 2000) =0
if T > 2000 K
`DeltaG` will be negative
The reaction would be spontaneus only beyond 2000 K .