Chapter 18, Problem 31R

To determine

The correct term related to the phrase.

Explanation of Solution

Introduction:

A crystal or crystalline solid is a solid material whose components (such as electrons, molecules, or ions) are organized in a closely ordered microscopic arrangement, forming a crystal lattice stretching in every direction. A crystalline substance that contains water is called as hydrate.

The crystalline substances which contain water molecules in them are called hydrate. As the water is hydrated, the water molecule is written by putting a dot after the chemical formula.

Example: $\text{Mg}{\left({\text{NO}}_{\text{3}}\right)}_{\text{2}}{\text{.4H}}_{\text{2}}\text{O,}{\text{CuSO}}_{\text{4}}{\text{.5H}}_{\text{2}}\text{O}$ .

Conclusion:

Hence, a crystalline substance that contains water represents hydrated compounds.