A cold pack may contain water and a solute that absorbs heat when it is dissolved.

Which term describes the dissolving process for this solute and solvent?

dissociation

heat of solution

exothermic

endothermic

This would be an endothermic reaction. The dissolving process is taking in heat, which perfectly describes endothermic reactions. The solute is acting as the module that will take the heat in, which will leave the area around it much colder than before the cold pack was used.