What is included in the name of a hydrate to indicate the amount of water present? a subscript

A Prefix.

Explanation: Compounds that have crystalline water present in them are known as hydrates. The coefficients written infront of in the formula of hydrates indicates how many water molecules are present in the hydrate.

While writing the names of the hydrates, prefixes like mono, di, tri, tetra, penta etc are included in the names of a hydrate to indicate the amount of water present.

For example, is Copper(II)sulfate penta hydrate .

In the name of above hydrate, penta hydrate is used since there are five water molecules present in the hydrate.

So, A prefix is included in the name of a hydrate to indicate the amount of water present.