test for gases

Question 1

ammonia nh3

Answer 1

test:
moist red litmus paper

observation:
colourless and pungent gas evolved turns moist red litmus paper blue

Question 2

chlorine cl2

Answer 2

test:
moist blue litmus paper

observation:
pale greenish-yellow and pungent gas evolved turns moist blue litmus paper red and then bleached

Question 3

sulfure dioxide so2

Answer 3

test:
filter paper soaked with acidified potassium manganate(VII) solution

observation:
colourless and pungent gas evolved turns purple acidified potassium manganate(VII) colourless

Question 4

carbon dioxide co2

Answer 4

test:
bubble gas through limewater CaOH2

observation:
colourless and odourless gas evolved forms white precipitate (CaCO3) when bubbled into limewater (CaOH2)

Question 5

water vapour h2o

Answer 5

test:
cobalt(II) chloride paper

observation:
colourless and odourless gas evolved turns blue cobalt(II) chloride paper pink

Question 6

oxygen o2

Answer 6

test:
insert a glowing splint into the test tube

observation:
colourless and odourless gas evolved rekindles a glowing splint

Question 7

hydrogen H2

Answer 7

test:
place a lighted splint at the mouth of the test tub

observation:
colourless and odourless gas evolved extinguishes lighted splint with a “pop” sound