Chapter 6, Problem 44E

Interpretation Introduction

Interpretation:

Water molecules associated with a formula unit of calcium chloride in CaCl₂. 2H₂O is to be written and the name of this compound is to be stated.

Concept introduction:

Some chemical compounds on crystallization from water solution produce crystals that contain water molecules as a part of their crystal structure. These water molecules of the crystals are called as water of crystallization or water of hydration. The crystal that results from the process of crystallization is referred as hydrate. Conversely, the water molecules can be driven away from the crystals by applying heat energy to afford anhydrous chemical compounds. The well-known example of a compound having water crystallization is CuSO₄.5H₂O. The anhydrous chemical compound CuSO₄ (colorless) is combined with 5 H₂O molecules on crystallization from a water solution result in hydrated CuSO₄.5H₂O (blue). The name of this chemical compound is denoted as copper (II) sulfate penta hydrate. In this case, the prefix ‘penta’ is usually referred as the presence of 5 molecules (water).