Question

In an estimation of sulphur by carius method 0.468 g of an organic compound gave 0.668 g of barium sulphate. Find the percentage of sulphur in the compound.

Answer 1

Molar mass of BaSO4 is 233 and 1mole BaSO4 contains 32g sulphur.

So 0.668 g BaSO4 will contain 32/233×0.668=0.091g sulphur

So 0.468 g organic sample contains 0.091 g sample

Hence % age of sulphur in the compound ls

= 0.091/0.468×100=19.6%

Answer 2

Mass of the compound = 0.468 g

Mass of the barium sulphate = 0.668 g

% of sulphur = 32 X Mass of barium sulphate X 100/ 233 X Mass of the compound

= (32 x 0.668 x 100)/(233 x 0.46)

= 19.60 %