Question

What is the difference between a hydrate and an anhydrate compound?

Answer 1

A hydrate is a substance that has a certain amount of water molecules. Calculating the mole-to-mole ratio between the water and anhydrate portions of the molecule is the first step in finding the formula of a hydrate.

Complete answer:

Hydrates	Anhydrates
Hydrate is a crystalline chemical compound or material that contains a water molecule as one of its constituents. Chemically, the water in these molecules mixes in a certain quantity. Water molecules surround and interact with solute ions or molecules in hydrate compounds. Water of hydration refers to the water molecules found in these substances.	The material that remains after the water has been removed from a hydrate is known as anhydrate. This is frequently accomplished by heating the chemical, which causes the water molecules to evaporate as steam.
Hydrates are ionic compounds that include free water molecules.	Whereas anhydrates are compounds that do not have any free water molecules.
When ionic chemicals are exposed to air and react with water molecules, hydrates are produced.	Anhydrates are the polar opposite of hydrates in that they don't contain any water molecules. Desiccants and drying agents are both terms for anhydrates.
Many ionic compounds exist in hydrated form, including Gypsum ($CaS{O_4}.2{H_2}O$), Borax ($N{a_3}{B_4}{O_7}.10{H_2}O$), and Epsom Salt ($MgS{O_4}{\text{ }}.7{H_2}O$).	One of the most widely utilised anhydrates is silica gel.
In the case of hydrates, the link is established between the molecule's cation and the water molecule. Heat can be used to eliminate the water molecules in hydrates.	The anhydrous substance, which differs from the hydrate in structure, is the result of heating.

Note:
Hydration is the process of adding water to a substance. Water molecules surround and interact with solute ions or molecules in this process. The type of water that is chemically coupled with a substance to create a hydrated compound is referred to as water of hydration. By simply heating the compound, the hydration water may be ejected.