In the Carius method for the estimation of sulphur, 0.200 g of an organic compound gave a precipitate of barium sulphate. If the percentage of sulphur in the compound is 16 % , the mass of barium sulphate formed is _______ mg . (Given: Atomic mass of Ba = 137 u , S = 32 u , O = 16 u )

Step-by-step solution

Molar mass of BaSO ₄ = 137 + 32 + 4 16 = 233 g mol ⁻¹ The percentage of sulphur is given by the formula: % S = 32 233 Mass of BaSO ₄ Mass of organic compound 100 Substituting the given values: 16 = 32 233 Mass of BaSO ₄ 0.200 100 16 = 3200 233 Mass of BaSO ₄ 0.200 Mass of BaSO ₄ = 16 233 0.200 3200 = 233 1000 g Mass of BaSO ₄ = 0.233 g = 233 mg Answer: 233