Question

Calculate the mass of sulphur trioxide produced by burning 64 g of sulphur in excess of oxygen. 

(Average atomic mass: S = 32 u, O = 16 u).

Answer 1

Given : 

Mass of sulphur (reactant) = 64 g 

To find : 

Mass of sulphur dioxide (product) 

Calculation : 

32 g of sulphur combine with 48 g oxygen to form 80 g of sulphur trioxide as follows :

Hence, 

(2 × 32 = 64 g) of sulphur will combine with (2 × 48 = 96 g) of oxygen to give (2 × 80 = 160 g) sulphur trioxide.

∴ Mass of sulphur trioxide produced = 160 g