IGCSE test for gases

Test for ammonia (NH₃)

• turns damp, red litmus paper blue

• turns limewater milky

• 'pops' with a lighted splint

• damp blue litmus paper turns red, then bleach to white

• relights a glowing splint

Test for carbon dioxide (CO₂)

• turns damp, red litmus paper blue

• turns limewater milky

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

• damp blue litmus paper turns red, then bleach to white

• relights a glowing splint

Test for chlorine (Cl₂)

• turns damp, red litmus paper blue

• turns limewater milky

• 'pops' with a lighted splint

• damp blue litmus paper turns red, then bleach to white

• relights a glowing splint

Test for hydrogen (H₂)

• turns damp, red litmus paper blue

• turns limewater milky

• 'pops' with a lighted splint

• damp blue litmus paper turns red, then bleach to white

• relights a glowing splint

Test for oxygen (O₂)

• turns damp, red litmus paper blue

• turns limewater milky

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

• damp blue litmus paper turns red, then bleach to white

• relights a glowing splint

Test for sulfur dioxide (SO₂)

• turns damp, red litmus paper blue

• turns limewater milky

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

• damp blue litmus paper turns red, then bleach to white

• relights a glowing splint