Q.

In the sulphur estimation, 0.20 g of a pure organic compound gave 0.40 g of barium sulphate. The percentage of sulphur in the compound is ______ ×10-1 %. (Molar mass: O = 16, S = 32, Ba = 137 in g mol-1)                [2025]


Ans.

(275)

Molar mass of BaSO4(MBaSO4)=[1×137+1×32+4×16]g mol-1=233g mol-1

Moles of BaSO4(nBaSO4)=Mass of BaSO4Molar mass of BaSO4=0.4233mol

Moles of S = Moles of BaSO4=0.4233mol

Mass of S=Moles of S×Molar mass of S=0.4233×32 g

Mass % of S in compound =Mass of SMass of organic compound×100

                                          =0.4233×320.2×100

                                          =27.5%=275×10-1%