Chemistry tests for metals, gases, anions and cations IGCSE

Test for carbonates

Add dilute acid, test for carbon dioxide (carbon dioxide produced, effervescence)

Test for chlorides

Acidify with dilute nitric acid, add aqueous silver nitrate (white ppt)

Test for bromide

Acidify with dilute nitric acid, add aqueous silver nitrate (cream ppt)

Test for iodide

Acidify with dilute nitric acid, add aqueous silver nitrate (yellow ppt)

Test for nitrate

Add aqueous sodium hydroxide, then aluminium foil, warm carefully (ammonia produced)

Test for sulphate

Acidify with dilute nitric acid, add aqueous barium nitrate (white ppt)

Test for sulphite

Add a small volume of acidified aqueous potassium manganate (VII) (purple to colourless)

Aluminium with sodium hydroxide

White ppt, soluble in excess giving colourless solution

Ammonium with sodium hydroxide

Ammonia produced

Calcium with sodium hydroxide

White ppt, insoluble in excess

Chromium (III) with sodium hydroxide

Green ppt, soluble in excess

Copper (II) with sodium hydroxide

Light blue ppt, insoluble in excess

Iron (II) with sodium hydroxide

Green ppt, insoluble in excess, ppt turns brown near surface on standing

Iron (III) with sodium hydroxide

Red-brown ppt, insoluble in excess

Zinc with sodium hydroxide

White ppt, soluble in excess giving colourless solution

Aluminium with aqueous ammonia

White ppt, insoluble in excess

Calcium with aqueous ammonia

No ppt or very slight white ppt

Chromium (III) with aqueous ammonia

Green ppt, insoluble in excess

Copper with aqueous ammonia

Light blue ppt, soluble in excess giving a dark blue solution

Iron (II) with aqueous ammonia

Green ppt, insoluble in excess, ppt turns brown near surface on standing

Iron (III) with aqueous ammonia

Red-brown ppt, insoluble in excess

Zinc with aqueous ammonia

white ppt, soluble in excess, giving a colourless solution

Test for ammonia

Turns damp red litmus paper blue

Test for carbon dioxide

Turns limewater milky

Test for chlorine

Bleaches damp litmus paper

Test for hydrogen

Squeaky ‘pop’ with a lighted splint

Test for oxygen

Relights a glowing splint

Test for sulphur dioxide

Turns acidified aqueous potassium manganate (VII) from purple to colourless

Lithium flame test

Red

Sodium flame test

Yellow

Potassium flame test

Lilac

Calcium flame test

Orange-red

Barium flame test

Light green

Copper (II) flame test

Blue-green