PRATICALS FOR UNIT 1

Question 1

Filtration

Answer 1

• Can be used to separate insoluble solids from liquids
• Can be used in purification
  e. g. solid impurities in the reaction mixture can be separated out using filtration

Question 2

Insoluble

Answer 2

The solid can’t be dissolved in he liquid

Question 3

What two ways can separate a soluble salt from a solution?

Answer 3

1. Evaporation
   (can only use it if the salt doesn’t decompose when it’s heated otherwise you’ll have to use:)
2. Crystallisation

Question 4

How to evaporate a soluble salt from a solution:

Answer 4

1. Pour solution into an evaporating dish
2. Slowly heat solution, solvent evaporated and solution gets more concentrated. Eventually, crystals start to form
3. Keep heating evaporation dish until all you have left are dry crystals

Question 5

How to use crystallisation to separate a soluble salt from a solution:

Answer 5

1. Pour solution in evaporating dish and gently heat he solution. Some of solvent evaporates, the solution gets more concentrated
2. Once some of the solvent has evaporated, or when you see crystals start to form remove dish from heat and leave solution to cool
3. Salt should start to form crystals as it becomes insoluble in the cold, highly concentrated solution
4. Filter crystals out of solution, leave them in warm place to dry. You could also use a drying oven or a dessicator