(Given Molar mass in g mol−1 S: 32, BaSO4: 233)
Correct Answer: 21.05%
In sulphur estimation, the sulphur present in the organic compound is completely converted into barium sulphate. Therefore, the mass of sulphur present can be calculated from the mass of barium sulphate obtained.
Moles of BaSO4 formed =
0.4813 / 233 = 0.002065 mol
From the formula of BaSO4, one mole of BaSO4 contains one mole of sulphur.
Moles of sulphur = 0.002065 mol
Mass of sulphur =
0.002065 × 32 = 0.0661 g
Percentage of sulphur in the compound =
(0.0661 / 0.314) × 100 = 21.05%
Hence, the percentage of sulphur present in the compound is 21.05%.
Updated for JEE Main 2026: This PYQ is important for JEE Mains, JEE Advanced and other competitive exams. Practice more questions from this chapter.