C4.2.1 Tests for Gases

• Hydrogen is a colorless and odorless gas that explodes with a 'pop' when ignited
• Match the gas with its primary test:

  Hydrogen ↔️ Ignite sample for 'pop'

  Oxygen ↔️ Relight glowing splint

  Carbon Dioxide ↔️ Turns limewater milky

  Ammonia ↔️ Turns red litmus blue
• Carbon dioxide turns limewater milky.


  True
• What color does blue litmus paper turn in the presence of an acidic gas?

  Red
• Red litmus paper turns blue in the presence of a basic gas.


  True
• The reaction between carbon dioxide and limewater produces a milky appearance due to the formation of calcium carbonate
• Match the gas with its properties:

  Hydrogen ↔️ Explodes with a 'pop'

  Oxygen ↔️ Supports combustion

  Carbon Dioxide ↔️ Extinguishes burning splint

  Ammonia ↔️ Turns red litmus blue
• Hydrogen is a colorless and odorless gas that explodes with a 'pop' when ignited
• Oxygen supports combustion and relights a glowing splint.


  True
• Ammonia gas turns damp red litmus paper blue
• What precipitate is formed when carbon dioxide reacts with limewater?

  Calcium carbonate
• Which primary test identifies hydrogen gas?

  Splint test
• Which test is used to identify carbon dioxide gas?

  Limewater test
• What color does blue litmus paper turn in acidic gases?

  Red
• What are gas tests used for in chemistry?

  Identify particular gases
• Oxygen supports combustion and relights a glowing splint.


  True
• Ammonia is a colorless gas with a pungent odor that turns damp red litmus paper blue
• Steps for using litmus paper to test gases

  1️⃣ Moisten litmus paper

  2️⃣ Expose litmus paper to gas

  3️⃣ Observe color change

  4️⃣ Determine if gas is acidic or basic
• Ammonia is a basic gas that turns damp red litmus paper blue
• What precipitate is formed when carbon dioxide reacts with limewater?

  Calcium Carbonate
• Limewater turns milky when carbon dioxide is bubbled through it.


  True
• Carbon dioxide turns limewater milky.


  True
• What sound does hydrogen gas produce when ignited in the splint test?

  'Pop'
• What does carbon dioxide do to a burning splint?

  Extinguishes it
• Ammonia is a basic gas that turns red litmus paper blue.


  True
• The splint test for hydrogen produces a distinct 'pop' sound due to rapid combustion
• Oxygen gas is identified by its ability to relight a glowing splint.


  True
• Ammonia gas turns damp red litmus paper blue
• The limewater test produces a milky white precipitate of calcium carbonate.


  True