1. Hydrated Ionic Compounds
Chemistry 11
Ms. McGrath

2. What is a hydrate?
A hydrate is an ionic compound that has crystallized with water molecule incorporated into its structure.
All hydrates have a specific amount of water molecules chemically bonded to each formula unit.

3. What is a hydrate? Example:
A raised dot, in front of one or more water molecules, in a chemical formula indicates a hydrated compounded - it does not mean multiplication! .
Example:
Epsom salts consists of magnesium sulfate heptahydrate – MgSO4·7H2O

4. Ionic Compounds
Ionic compounds that have water molecules associated with them are called Hydrated Ionic Compounds
Ionic compounds that do not have water molecules associated with them are called Anhydrous

5. Determining the Formulae of a Hydrate
A hydrate of barium hydroxide, Ba(OH)2·xH2O, is used to make barium salts and to prepare certain organic compounds.
a) A 50.0 g sample of the hydrate contains 27.2 g of Ba(OH)2. Calculate the percent, by mass, of water in the hydrate of barium hydroxide.
b) Find the value of x in Ba(OH)2.