This Section is meant to be sort of an extenuation of Thermodynamics, or thermochemistry. This section will just talk about how temperature and energy effect if a reaction will be spontaneous or not. The way we use the word spontaneous here is if the reaction will occur at all, so if a reaction is spontaneous it will occur, if it is not spontaneous, it will not occur. Again, please do not just rely on this text to provide information for a class, as they may or may not be complete enough for your particular study.
Major Equations
There are two parts to this section, the prediction of spontaneity and the equations to find the different things in thermochemistry. To learn more than this, please go to the section on thermochemistry for more depth.
Predicting Spontaneity
To determine if a reaction will be spontaneous, solve for Delta G and look at the sign. If the sign is negative then the reaction will occur, it is spontaneous. If the sign is positive then the reaction will never occur, so it is nonspontaneous.
| Case | Delta H | Delta S | Delta G |
| I | - | + | (-) Spontaneous at all temperatures |
| II | + | - | (+) Nonspontaneous at all temperatures |
| III | + | + | (+) Nonspontaneous at low temperatures (-) Spontaneous at high temperatures |
| IV | - | - | (-) Spontaneous at low temperatures (+) Nonspontaneous at high temperatures |