Preparation: Mixing together elements and compounds. For an aqueous solution, add water.

Separation and purification:

- Distillation. Salty water is heated so that the water evaporates and condenses back into water in the condenser, leaving behind the salt in the flask.

- Filtration. Used to separate an insoluble solid from a liquid.

Crystallisation: Evaporating the solution to a much smaller volume and then leaving it to cool. As the solution cools, crystals form and these can be obtained by filtration.

Acid + Alkali -> Salt + Water

Hydrochloric Acid + Sodium Hydroxide -> Sodium Chloride + Water

Hal + NaOH -> NaCl + H2O

Add 30cm^2 of sodium hydroxide to a flask

Add 2 drops of the indicator phenolphthalein

Add the hydrochloric acid to the flask

The solution will turn colorless when neutralized

Heat the solution to evaporate the liquid and obtain the salt

Acid + Metal -> Salt + Hydrogen

Sulphuric Acid + Zinc -> Zinc Sulphate + Hydrogen

H2SO4 + Zn -> ZnSO4 + H2

Add zinc to a flask of the acid

When zinc dissolves, hydrogen bubbles will appear

Filter the solution to remove the excess zinc

Heat the solution to evaporate the liquid and obtain the salt

Acid + Base -> Salt + Water

Sulphuric Acid + Iron (II) Oxide -> Iron Sulphate + Water

H2SO4 + FeO -> FeSO4 + H2O

Add and excess iron oxide to the sulphuric acid

Filter the solution to remove the excess iron oxide

Heat the solution to evaporate the liquid and obtain the salt

Describe the following tests to identify aqueous cations

Ammonium -> Add dilute sodium hydroxide, warm up -> Ammonia gas is released, damp red litmus paper turns blue

Copper (II) -> Add dilute sodium hydroxide or ammonia solution -> A blue precipitate forms

Iron (II) -> Add dilute sodium hydroxide or ammonia solution -> A pale green precipitate forms

Iron (II) -> Add dilute sodium hydroxide or ammonia solution -> A red - brown precipitate forms

Zinc -> Add dilute sodium hydroxide or ammonia solution -> A white precipitate forms