How does enthalpy affect the spontaneity of a reaction?

1 Answer
Oct 3, 2015

DeltaG=DeltaH - TDeltaS

Explanation:

Spontaneity is governed by free energy DeltaG. The relationship between the change on free energy DeltaG and change on enthalpy DeltaH is:

DeltaG=DeltaH - TDeltaS
where DeltaS is the change on entropy.

For spontaneous processes, DeltaG has to be negative. In order to predict the sign of DeltaG, we will need to watch for the sign of DeltaH and the term TDeltaS. Here is a table that explains this:

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Here is a video that explains this in details;