IGCSE Chemistry: Tests and gas tests for anions

ammonia (NH3)

turns damp, red litmus paper blue

carbon dioxide (CO2)

Turns limewater milky

Chlorine (Cl2) gas

bleaches damp litmus paper

hydrogen (H2)

'pops' with a lighted splint

oxygen (O2)

Relights a glowing splint

Sulfur Dioxide (SO2)

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

carbonate (CO3 2-) - add dilute acid

effervescence, carbon dioxide produced

chloride (Cl-) - acidify with dilute nitric acid, then add aqueous silver nitrate

white ppt.

bromide (Br-) - acidify with dilute nitric acid, then add aqueuous silver nitrate

cream ppt.

iodide (I-) - acidify with dilute nitric acid, then add aqueuous silver nitrate

yellow ppt.

nitrate (NO3-) - add aqueous sodium hydroxide, then aluminium foil; warm carefully

ammonia produced

sulfate (SO4 2-) - acidify, then add aqeuous barium nitrate

white ppt.

sulfite (SO3 2-) - add dilute hydrochloric acid, warm grently and test for the presence of sulfur dioxide

sulfur dioxide produced will turn acidified aqeuous potassium manganate(VII) from purple to colourless