Testing for gases

Question 1

how do we test for hydrogen

Answer 1

remove the bung and insert a burning splint in the tube

hydrogen gas burns rapidly and produces a pop sound

Question 2

how can we test for oxygen

Answer 2

a tube contains a gas which might be oxygen

use a glowing splint by placing it into a test tube of oxygen, the splint relights

Question 3

how can we test for carbon dioxide?

Answer 3

limewater is used
limewater is an aqueous solution of calcium hydroxide

draw some of the gas into a plastic pipette

bubble the gas through the limewater

repeating this several times will make the limewater turn cloudy

cloudy means the gas was carbon dioxide

Question 4

what is limewater

Answer 4

an aqueous solution of calcium hydroxide

Question 5

how do we test for chlorine

Answer 5

we insert damp litmus paper into the mouth of the test tube

chlorine bleaches the litmus paper and turns it white