Question

If you had observed the fate of an ice cube at 25 degrees Celsius, what would you conclude about the spontaneity of the process H2O (s) <-> H2O (l) ?

I know for it to be spontaneous, delta G has to be negative, but how can I determine the delta G with the info given in the question?

Answer 1

I don't think the question is asking you to determine dGrxn. I think the question is asking, "Is the rxn spontaneous or not?" and the answer is yes it is. If you look at dStotal = dSsurr + dSrxn
dSrxn is + since liquid H2O has higher entropy than solid H2O and dsurroundings is q/T so dStotal is + and that means the reaction is spontaneous.