Thermodynamics  

Thermodynamics deals with energy interactions in a chemical reaction. When you select thermodynamics from the Energy Calculations section, you will see three options: enthalpy, entropy, and Gibbs free energy. All three deal with the  energy interactions between reactants and products in a chemical reaction.

When you select enthalpy from the list of options, you will see that you need to have the enthalpy totals for the reactants and the enthalpy totals for the products. These values you can look up in the table at the bottom of the main screen or in your text. From a balanced equation, you will also need the coefficients of each substance.

Entropy refers to the amount of disorder in a reaction. Solids going to a liquid or a liquid going to a gas are common examples of increased disorder or entropy.

Gibbs free energy refers to the tendency of a reaction to be spontaneous.  It requires the enthalpy change, the entropy change, and the Kelvin temperature. If the free energy value is negative then the reaction is spontaneous.

