Topic 3 - Water Of Crystallisation

Question 1

what do all solid salts consist of?

Answer 1

a lattice of positive and negative ions

Question 2

what is the difference between a hydrated salt and an anhydrous salt?

Answer 2

in some salts, water molecules are in the lattice. these molecules are called water of crystallisation. hydrated salts have water of crystallisation.

Question 3

if you know the mass of the salt when it’s hydrated and anhydrous, how do you work out the formula?

Answer 3

1. work out the mass of both salts
2. work out the mass of water lost and the number of moles
3. calculate the number of moles of anhydrous salt
4. work out the ratio of anhydrous salt to water
5. round the result