0.395 g of an organic compound by Carius method for the estimiation of sulphur gave 0.582 g of BaSO₄. the percentage of sulphur in the compound is:

Mass ${\mathrm{BaSO}}_4$ = 0.582 g  

We know $$\begin{gathered} {\mathrm{BaSO}}_4\equiv \mathrm{S} \\ 233 32 \end{gathered}$$  

233 g of ${\mathrm{BaSO}}_4$ contain sulphur = 32 g    

0.582 g of ${\mathrm{BaSO}}_4$ contains sulphur $=\frac{32}{233}\times 0.582$    

Percentage of sulphur $$\begin{gathered} =\frac{\mathrm{Wt}. \mathrm{of} \mathrm{sulphur}}{\mathrm{Wt}. \mathrm{of} \mathrm{compound}}\times 100 \\ =\frac{32\times 0.582}{233\times 0.395}\times 100= 20.24\% \end{gathered}$$

 Hence, the correct answer is (A).