Question

For an exothermic dissolving process, predict the signs for the change in enthalpy, entropy, and free energy and explain how temperature will affect these changes.

Answer 1

G=H-T×S
G is free energy
H is enthalpy
T is temperature
S entropy change

When you dissolve a solid S becomes positive
An exothermic reaction has a negative H

For a reaction to be feasible G must be 0< less than 0 so negative

So if G = -H - (T×+S) according to your question then G is always negative so the reaction is feasible at any temperature above 0 kelvin

Hope that helps

Answer 2

For any thermodynamic process the relation between enthalpy, free energy and entropy change is

ΔG = ΔH -TΔS

Where

ΔG = free energy change

ΔH = enthalpy change

ΔS = entropy change

T = temperature

Now for a spontaneous reaction

ΔG should be negative

For an exothermic reaction

ΔH = negative

And reaction will be feasible at high temperature as it will make the Value of ΔG negative.