A salt dissolves in water and the beaker becomes noticeably colder. What does this reveal about how added heat affects the salt's solubility?

Core Concept

Cooling during dissolving shows the process absorbs heat from the surroundings, so heat acts like a reactant. Supplying extra heat then pushes the dissolving equilibrium forward by Le Chatelier's principle. More solid enters solution at the higher temperature, raising solubility. Ammonium nitrate is the familiar example whose dissolving chills the solution.