09. Recovery of soluble salts by recrystallisation

What can reactions often yield?

Impure products which need to be purified by recrystallisation

Give examples of impure products?

Side products, unreacted materials or anti bumping granules

1) What is the first step?

Hot solvent added to compound dropwise until it has been dissolved

1) How is the solvent chosen?

Chosen so that the compound is soluble when hot but less soluble when cold

2) what is the second step?

Solid and soluble impurities dissolve into solvent leaving insoluble impurities behind

3) What is the third step?

Solution filtered while hot through warm filter, which collects insoluble materials and anti bumping granules

4) what is the fourth step?

As temp of solution falls, so does solubility of compound -> eventually crystals of purified compound begin to separate and soluble impurities remain in solution

5) what is the last step?

Compound can be collected by filtration and dried