Testing for Gases

Question 1

Testing for Chlorine

Answer 1

• Damp blue litmus paper
• Bleaches white in the presence of chlorine gas
• May turn red first when water is dissolved, as acidic hydrochloric acid is formed

Question 2

Safety Precaution of Testing for Chlorine

Answer 2

• chlorine gas is poisonous
• operate within a fume cupboard
• wear a mask

Question 3

Testing for Oxygen

Answer 3

• glowing splint
• relights in presence of oxygen

Question 4

Testing for Hydrogen

Answer 4

• burning splint
• burns with squeaky pop
• heat energy causes hydrogen to burn with oxygen in the air
• produces water

Question 5

Testing for Carbon dioxide

Answer 5

• attach bung onto gas sample with the other end in limewater (calcium hydroxide)
• bubble the gas through
• limewater turns cloudy in the presence of carbon dioxide
• calcium carbonate solids formed grant a cloudy appearance