Answer to Question #130876 in General Chemistry for Ruth

Question

Why is solvent solute interaction either endothermic or exothermic? How?

Answer 1

Solvent-solute interactions involve the breaking and formation of new bonds. Some of these interactions require more energy to break bonds than the energy released when new bonds are formed. This situation leads to overall endothermic reaction. However in other interactions, the energy absorbed during bond breaking process is less than the energy released when new bonds are formed. In overall, the interactions end up releasing more energy than the energy absorbed. This situation leads to exothermic reaction.