T8 - Chemical Analysis - Ion Tests

Flame Tests (+)

Potassium - Lilac

Sodium - Yellow

Lithium - Crimson

Copper - Green

Calcium - Orange-red

Sodium Hydroxide Test (+)

Copper (II) - Blue precipitate

Iron (II) - Green precipitate

Iron (III) - Brown precipitate

WHITE PRECIPITATE:

> Magnesium

> Calcium - also orange-red flame test

> Aluminium - dissolves if excess NaOH added

Carbonate Ion Test (-)

- Add some dilute acid (metal carbonate + acid = salt + water + CO2)

- Bubble the gas formed through limewater

- If limewater turns cloudy = carbonate ions present

Halide Ions Test (-)

- Add some dilute nitric acid (removes impurities - can't use HCl obviously as it has chloride ions in it)

- Add some dilute silver nitrate

Results:

Chloride = white

Bromide = cream

Iodide = yellow

Sulfate Ions Test (-)

- Add some dilute hydrochloric acid (remove impurities)

- Add some barium chloride

- White precipitate = sulfate ions present