Question

Are energy changes always involved when substances dissolved in water

Answer 1

Yes i believe there are energy changes when substances are dissolved in water which are either exothermic or endothermic. When a substance is dissolved in water and temperature goes up, heat is released or produced which is called exothermic change. Most substances dissolve in water lowering the temperature and are endothermic changes as energy is absorbed. For example when sodium chloride dissolves in water there is very little change in temperature which is exothermic.