Concept:Water chemically combined within a crystal lattice is known as water of crystallization.Explanation:When salts form crystals, some water molecules become part of the crystal structure. This fixed amount of water is not ordinary water; it is chemically combined with the substance. For example, in CuSO4⋅5H2O, the 5H2O is water of crystallization. Such compounds are called hydrates. Therefore, the term for the amount of water combined with a substance is water of crystallization.Answer:D. crystallization