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Explain the estimation of phosphorus and sulphur present in the organic compound |
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Answer» Solution :Estimation of sulphur: A known mass of the ORGANIC compound is heated with sodium peroxide in a Carius tube. Then S is oxidised to `H_(2)SO_(4)`. The acid is precipitated as `BaSO_(4)` by adding excess of `BaCl_(2)` aq. Solution. The ppt. is filtered, wahed, dried and weighed. Calculations: Mass of organic compound =ag Mass of barium sulphate =bg Molecular weight of `BaSO_(4)=233` 1 mole of `BaSO_(4) or 233 G of BaSO_(4)` contains 32g of sulphur `THEREFORE b g" of "BaSO_(4)` contains ........? `=(32 xx b)/(233)` g of sulphur a g of organic compound contains `(32 xx b)/(233)" g of sulphur"` 100 g organic compounds ..........? `=(100 xx 32 xx b)/(a xx 233)" g of sulphur (% of S)"` Estimation of phosphorus : A known mass of organic compound is heated with funning nitric acid in a Carius tube. Then phosphorus is oxidised to phosphoric acid. The acid is precipitated as AMMONIUM phosphomolybdate by adding AMMONIA and ammonium molybdate solutions. Calculation: Mass of organic compound=a.g. Mass of ammonium phosphomolydate =bg Molecular weight of ammonium phosphomolybdate =1877 1877g of ammonium phosphomolybdate conatains 31 g of phosphorus b'g of ..............? `=(31 xx b)/(1877)` g of phosphorus. 'a g of organic compound contains `(31 xx b)/(1877)` g of phosphorus `=(100 xx 31 xx b)/(a xx 1877)" g of P(% of P)"` |
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