Describe the laboratory preparation of dry oxygen gas. – NABTEB QUESTION

1. Heat potassium trixochlorate V in the presence of manganese iv oxide (as a catalyst) in the ratio 4:1 by mass in a hard test tube fitted with a delivery tube.

2. The oxygen gas produced from the mixture is passed through a U tube containing (anhydrous) calcium chloride to dry.

3. The issuing gas is collected over mercury in gas jar or test tube.

4. 2KCl03 (MnO2) → 2KCl + 3O2.