Consider the process known as hydration during aqueous solution formation. (a) What is hydration? (b) Does it release or absorb energy? Explain.

Hydration is the process in which water molecules surround and interact with ions or molecules within a substance, causing it to dissolve in water and forming an aqueous solution. The water molecules form hydrogen bonds with charged populations, stabilizing them in the solution.

Hydration can either release or absorb energy. Typically, it is an exothermic process, meaning that energy is released when the water molecules interact with the solute particles. This occurs when the energy released from the new hydrogen bonds formed between the water molecules and the solute particles is greater than the energy required to break the intermolecular forces within the solute and the hydrogen bonds within water. However, in some cases, the hydration process may be endothermic, meaning it absorbs energy. This occurs when the energy required to break the intermolecular forces within the solute and the hydrogen bonds within water is greater than the energy released from the new hydrogen bonds formed between the water molecules and the solute particles. As a result, the net energy change is positive, and the process absorbs energy from the surroundings.