Concept:Hydration energy greater than lattice energy makes the overall dissolving process release heat.Explanation:For an ionic compound to dissolve, lattice energy breaks apart the crystal structure. Hydration energy is released when water molecules surround the separated ions. Since hydration energy is greater than lattice energy, the extra energy is given off as heat. A reaction that releases heat to the surroundings is called an exothermic reaction.Answer:D. An exothermic reaction