The temperature plays an important role in determining the Gibbs free energy and spontaneity of a reaction. ... If ΔH is negative, and –TΔS positive, the reaction will be spontaneous at low temperatures (decreasing the magnitude of the entropy term).

Do spontaneous reactions depend on temperature?

In this case, a spontaneous reaction is dependent upon the TΔS term being small relative to the ΔH term, so that ΔG is negative. ... It is spontaneous only at a relatively low temperature. Above 273 K, the larger TΔS value causes the sign of ΔG to be positive, and freezing does not occur.

What is spontaneity determined by?

The best indicator of spontaneity in a reaction is the change in Entropy (S or DS). The Second Law of Thermodynamics states that for a reaction to be spontaneous, there must be an increase in entropy. Entropy is often defined as a measure of the disorder of a system, this is not a very accurate definition.