In the following examples comparing acid strength down a group we will interpret the given thermodynamic data for four acids (HF, HCl, HBr, and HI) reacting with water.
1. Lets first explore enthalpy of the reaction.
d. Here is the reaction enthalpy data for the four acids when reacting with water.
Thinking about the energy required to break bonds and energy released when
forming new bonds explain why all of these reactions are exothermic.