IGCSE Chemistry- Water of Crystallisation

Water of Crystallisation 

Salts can be Anhydrous or Hydrated

• All solid salts consist of lattice positive and negative Ions
• In some salts, water molecules are incorperated in the lattice too
• The water in the lattice is called water of cystallisation 
• A solid salt containing water of crystallisation is Hyrdrated
• If the salt doesnt contain any water of crystallisation, it's call Anhydrous

Hydrated Salts

The water molecules in hydrated salts have a small positive charge on the hydrogen atoms and a small negative charge on the oxygen atoms. This means they are attracted to the ions in the lattice and are held in place. 

You can calculate How much water of crystallisation a salt contains 

• 
  One mole of a Hydrated salt always has a particular number of moles of water of crystallisation- It's formula shows how many
• For example Hydrated copper sulfate has 5 moles of water for every one mole of salt…