For a chemical reaction the values of DeltaH and DeltaS at 300 K are - 10 kJ mol^(-1)and-203 K^(-1)mol^(-1) respectively. What is the value of DeltaG of the reaction? Calculate the DeltaG of a ran. at 600K assuming DeltaH and DeltaS values are constantDeltaHand DeltaS values are constant. Predict the nature of the reaction.

For a chemical reaction the values of DeltaH and DeltaS at 300 K are -

1.	For a chemical reaction the values of DeltaH and DeltaS at 300 K are - 10 kJ mol^(-1)and-203 K^(-1)mol^(-1) respectively. What is the value of DeltaG of the reaction? Calculate the DeltaG of a ran. at 600K assuming DeltaH and DeltaS values are constantDeltaHand DeltaS values are constant. Predict the nature of the reaction.
Answer» Solution :Given: `DeltaH = -10 kJ mol^(-1) = -10000 J mol^(-1)` `DeltaS = - 20 JK^(-1)mol^(-1)` `T = 300 K` `DeltaG = ?` `DeltaG = DeltaH-TDeltaS` `DeltaG = - 10 kJ mol^(-1)- 300 K xx (-20xx10^(-3) ) kJ K^(-1)mol^(-1)` `DeltaG = (-10+6) kJ mol^(-1)` `DeltaG = (- 4 kJ mol^(-1)` At 600 K `DeltaG = -10 kJ mol^(-1)- 600 K xx (-20 xx10^(-3) ) KJ K^(-1)mol^(-1)` `DeltaG = (-10 + 12) kJ mol^(-1)` `DeltaG = + 2 kJ mol^(-1)` The value of `DeltaG` is NEGATIVE at 300K and the reaction is spontaneous, but at 600K the value `DeltaG` becomes positive and the reaction is non-spontaneous.