(a) Taking hydrogen peroxide, how would you prepare oxygen in the laboratory?

(b) What is the role of manganese dioxide in the preparation of oxygen?

(c) Write the balanced chemical equation for the above chemical reaction.

(d) Why is hydrogen peroxide preferred in the preparation of oxygen gas?

(e) Why is oxygen collected by downward displacement of water?

(f) What happens when a glowing splinter is introduced in a jar containing oxygen?

(g) What happens when oxygen gas is passed through alkaline pyrogallol solution?

(a) What happens when (i) mercuric oxide and (ii) potassium nitrate are heated?

(b) Why is potassium chlorate not used for laboratory preparation of oxygen?

Name the three types of oxidation processes. In which of these, large amount of heat and light energy are produced?

What do you observe when the following substances are heated and then tested with moist blue and red litmus paper?

(a) Sulphur

(b) Phosphorus

(c) Calcium

(d) Magnesium