Sulphur burns in oxygen to give sulphur dioxide. If 16 g. of sulphur burns in ‘x’ cc. of oxygen, calculate the amount of potassium nitrate which must be heated to produce ‘x’ cc. of oxygen. [S = 32, K = 39, N = 14, O = 16].

2KNO₃  →  2KNO₂   +   O₂

202 g                               32 g

S    +    O₂   →   SO₂

32 g

32 g of sulphur requires 202 g of potassium nitrate to be heated

∴ 16 g of sulphur will require 202\over32 × 16

= 101 g of potassium nitrate.

Hence, amount of potassium nitrate which must be heated is 101 g