1What might be the cause of suffocation inside a deep well?
2What might be the cause of breathlessness inside a cave?
3Which chemicals are used to prepare carbon dioxide in the laboratory? Write the balanced equation.
4Why is carbon dioxide collected by upward displacement of air?
5State two precautions taken while preparing carbon dioxide, with reasons.
6What happens when carbon dioxide is passed through lime water for a short time, and then for a long time? Give equations.
7What is seen when burning magnesium is put into a jar of carbon dioxide? What does it prove?
8How does a fire extinguisher work? Write the chemical equation.
9Why does water rise in an upturned test tube of carbon dioxide when potassium hydroxide is added?
10What is dry ice? Give one use.
11What is carbogen and what is it used for?
12State the contribution of Van Helmont, Joseph Black and Lavoisier to the discovery of carbon dioxide.
13Why do soft drinks taste sour, and why do bubbles come out when the bottle is opened?