Suppose that a mixture of ice and water is placed in a refrigerator that is held at the freezing point of water, exactly 0.0C. Calculate deltaS for the ice-water mixture, deltaS for the refrigerator, and deltaStotal when 5.00g of ice forms. Is this process spontaneous? Is the reverse process spontaneous?
H2O(l) ==> H2O(s)
delta S rxn = S(solid) - S(liquid)
delta S will be in J/mol. Convert that to 5.00 grams. That gives you dS for the system. dS surrounds = - dHfusion/T (and T is 273, not zero).
dS total = dSsystem + dSsurroundings.
reactions are spontaneous is dS total is +.