1. Separating Mixtures Lesson 5: Extracting Salt
Which of the descriptions below describes a mixture? What is the other box describing?
Two or more different substances that are not chemically joined A B
Two or more different atoms that are chemically joined

2. Mixture
A mixture is made up of 2 or more different atoms or molecules. They are not chemically joined and so can be easily separated.
E.g. iron and sulphur S S Fe Fe S Fe

3. Separating Techniques
Filtration – we use filtration when we want to separate particles of solids from a solvent (liquid). The particles are trapped in the filter paper, and the solvent passes through.

4. Separating Techniques
Evaporation – we use evaporation when we want to remove liquid from a mixture of liquid and dissolved solids. The liquid evaporates and leaves the solid behind.
HEAT

5. Separating Salt and Sand
Step 2: Add 50ml of water to the mixture in a beaker
Step 1: Collect a mixture of salt and sand
stirring rod
Salt and sand mixture
impure salt solution
beaker
Step 3: Filter the sand and salt solution.
Step 4: Evaporate the water from the pure salt solution
sand
filter funnel
evaporating dish
filter paper
gauze
test tube
pure salt solution
tripod
HEAT