Draw a neat labelled diagram to prove that oxygen is non-combustible, but supports combustion.

Select the correct answer from the choice in bracket to complete each sentence.

1. Nitrogen of the air is utilized by plants for formation of …………… [carbohydrates/proteins]

2. The gas evolved as a product of combustion as well as respiration is ……………[nitrogen dioxide / carbon dioxide].

3. A candle burns in a jar of oxygen, but gets extinguished in …………… [chlorine/nitrogen]

4. Air has variable composition and hence there is …………… [less/more] oxygen at lower altitudes than at higher altitudes.

5. Rusting is a chemical reaction which involves …………… [rapid/slow] oxidation.

Draw a neat labelled diagram to prepare oxygen in the laboratory from hydrogen peroxide and a catalyst.

Draw a neat labelled diagram to determine the component of air used up in burning, by using phosphorus and a bell jar.