Testing For Hydrogen, Oxygen, Carbon Dioxide & Chlorine

The video tutorial explains how to test for the presence of various gases in the laboratory, including hydrogen, oxygen, carbon dioxide, ammonia, and chlorine. It highlights the importance of testing gases due to their colorless and odorless nature. The tutorial provides specific methods for each gas: hydrogen is identified by a squeaky pop sound, oxygen by relighting a glowing splint, carbon dioxide by turning lime water milky, ammonia by changing red litmus paper to blue and forming white smoke with hydrochloric acid, and chlorine by turning blue litmus paper red and bleaching it. The video concludes with a summary of these testing methods.

Why is it necessary to test gases in the laboratory?

• Because gases have distinct colors and odors.

• Because gases are easy to identify by their weight.

• Because gases are difficult to identify by appearance alone.

• Because gases are always toxic.

What sound indicates the presence of hydrogen when tested with a lit splint?

• A loud bang

• A soft hiss

• A squeaky pop

• No sound at all

What happens to a glowing splint in the presence of oxygen?

• It makes a popping sound.

• It changes color.

• It relights.

• It extinguishes.

How can you confirm the presence of carbon dioxide using lime water?

• The lime water turns clear.

• The lime water changes to blue.

• The lime water evaporates.

• The lime water turns milky.

What color change occurs when chlorine is tested with damp blue litmus paper?

• It turns red and then bleaches to white.

• It turns green and then fades.

• It turns yellow and then darkens.

• It remains blue.