For the reactions at 298 K, `2A + B to C, Delta H = 400 kj mol^(-1) and Delta S = 0.2 kj K^(-1) mol^(-1)`. At what temperature will the reaction become spontaneous considering `Delta H and Delta S` to be constant over the temperature range ?

Explanation

We are given that
`Delta H = 400 kj mol^(-1)`
`Delta S= 0.2 kjK^(-1) mol^(-1)`
We are to find out the temperature.
Using the relation , `Delta G = Delta H - T Delta S`
`Delta G = 0, Delta H = T Delta S or T = (Delta H)/(Delta S) , T = (400 kj mol^(-1))/(0.2 kj K^(-1) mol^(-1)) = 2000 K.`