Answer 1

The molecular formula of sodium sulphate is Na₂SO₄

Molar mass of Na₂SO₄ = [(2 × 23.0) + (32.066) + 4 (16.00)] = 142.066 g

`"Mass percent of an element "="Mass of the element in the compound"/"Molar mass of the compound"xx100`

∴ Mass percent of sodium :-

`=(46.0g)/(142.066g)xx100`

 = 32.379

= 32.4%

Mass percent of sulphur :-

`=(32.066g)/(142.066g)xx100`

= 22.57

= 22.6%

Mass percent of oxygen :-

`=(64.0g)/(142.066g)xx100`

= 45.049

= 45.05%