Test for gases

Question 1

Hydrogen

Answer 1

Lighted splint / lit splint - squeaky pop when held above the mouth of the test tube

Question 2

Oxygen

Answer 2

Glowing splint - relights

Question 3

Carbon dioxide

Answer 3

Limewater - goes cloudy/milky (precipitate of calcium carbonate)

Question 4

Ammonia

Answer 4

Damp red litmus paper / damp universal indicator paper - blue
Gives a dense white smoke with HCl gas from the stopper of a bottle of concentrated acid

Question 5

Chlorine

Answer 5

Wet litmus paper - white / bleaches

Question 6

Nitrogen dioxide

Answer 6

Purple acidified potassium mangnate (VII) - turns colourless

Damp blue litmus paper - red

Question 7

Sulfur dioxide

Answer 7

Purple acidified potassium manganate (VII) - turns colourless
Acidified potassium dichromate (VI) - turns orange to green
Both are used soaked onto filter paper held in the gas

Question 8

Hydrogen chloride

Answer 8

Aqueous silver nitrate - white precipitate

NH3 - gives a dense white smoke