5.2.3 - gas tests

Question 1

test for hydrogen

Answer 1

squeaky pop test:

1) collect a sample of gas in a test tube
2) attempt to ignite it using a lit splint

result: squeaky pop sound

pop sound is caused by hot gas rushing out of test tube

Question 2

test for oxygen

Answer 2

glowing splint test:

1) collect a sample of gas in a test tube
2) place a glowing splint into the test tube

result: splint relights

Question 3

test for the presence of water

Answer 3

copper sulphate test

1) add anhydrous copper sulphate (CuSO4)

changes colour from white to blue

Question 4

test for the purity of water

Answer 4

measure boiling point and melting point

boiling point- 100 degrees celsius
melting point- 0 degrees celsius

Question 5

test for carbon dioxide

Answer 5

limewater test:

1) bubble a sample of gas through limewater

a white precipitate forms

Question 6

test for chlorine

Answer 6

damp blue litmus test

1) place the damp blue litmus paper in a sample of gas

it turns white (bleaches)

Question 7

test for ammonia

Answer 7

damp red litmus test

1) place damp red litmus paper in a sample of gas

turns blue