In the Carius method for the estimation of sulphur, 0.16 g of an organic compound yielded 0.233 g of barium sulphate. What is the minimum molecular mass of the organic compound? (Given: Molar mass of S = 32 g mol ⁻¹ , Molar mass of BaSO ₄ = 233 g mol ⁻¹ )

Step-by-step solution

First, calculate the mass of sulphur present in the given mass of BaSO ₄ : Mass of S = 32 233 0.233 = 0.032 g Next, find the percentage of sulphur in the organic compound: % S = 0.032 0.16 100 = 20 % For the minimum molecular mass, the compound must contain exactly one atom of sulphur per molecule. Therefore, 20 % of the minimum molecular mass ( M ) must equal the molar mass of one sulphur atom ( 32 g mol ⁻¹ ). M 20 100 = 32 M = 32 100 20 = 160 g mol ⁻¹ Answer: 160 g mol ⁻¹