Testing for Gases (Cognito Video)

Which gases are covered in the video tutorial?

• Chlorine, Oxygen, Hydrogen, and Methane

• Chlorine, Nitrogen, Hydrogen, and Carbon Dioxide

• Chlorine, Oxygen, Hydrogen, and Carbon Dioxide

• Chlorine, Oxygen, Nitrogen, and Carbon Dioxide

What color does blue litmus paper turn when exposed to chlorine?

• White

• Green

• Yellow

• Red

Why might blue litmus paper briefly turn red before turning white when testing for chlorine?

• Because chlorine forms hydrochloric acid with water

• Because chlorine forms sulfuric acid with water

• Because chlorine forms acetic acid with water

• Because chlorine forms nitric acid with water

What safety precaution should be taken when testing for chlorine?

• Wear a mask or use a fume cupboard

• Wear gloves

• Wear a lab coat

• Wear safety goggles

What happens to a glowing splint when it is placed in a tube of oxygen?

• It makes a popping sound

• It turns blue

• It relights

• It extinguishes

What is required for the test of oxygen?

• A glowing splint

• A burning splint

• A beaker of water

• A piece of litmus paper

What sound is produced when hydrogen is tested with a burning splint?

• No sound

• A squeaky pop

• A hissing sound

• A loud bang

What is formed when hydrogen burns with oxygen in the air?

• Hydrochloric acid

• Water

• Sulfur dioxide

• Carbon dioxide

What happens to lime water when carbon dioxide is bubbled through it?

• It remains clear

• It turns blue

• It turns red

• It goes cloudy

What solid is formed when carbon dioxide reacts with calcium hydroxide?

• Calcium sulfate

• Calcium chloride

• Calcium nitrate

• Calcium carbonate