0.316 g of an organic compound, after heating with fuming nitric acid and barium nitrate crystals in a sealed tube gave 0.466 g of the precipitate of barium sulphate. Determine the percentage of sulphur in the compound.
(Atomic masses : Ba = 137, * = 32, O = 16, C = 12, H = 1).
Mass of the substance taken = 0.316 g
Mass of BaSO4 formed = 0.466 g
Molecular mass of BaSO4 = 137 + 32 + 64 = 233
Then, mass of * in 0.466 g of BaSO4
= 0.466 x 32 / 233 g
Percentage of * in compound
= 0.466 x 32 x 100 / 233 x 0. 316
= 20.25
