both ΔH^o and ΔS^o change only a little with temperature
both ΔH^o and ΔS^o change in the same direction so the effect tends to cancel somewhat during subtraction

This general method is limited to standard atmospheric pressure and 1 M concentrations (for ions in solution), however. A further treatment is beyond our needs at this level.

Some additional thought about the Gibbs-Helmholtz equation will reveal that the relationship it describes can be used to predict those reactions which can be manipulated by changing temperature.

A decision on the spontaneity of a reaction using ΔG^o is frequently not an either/or matter. We say that a process is "non-spontaneous" if ΔG^o > 0 but we can see from the previous example that temperature might change that situation.