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For the estimation of nitrogen, 1.4 g of an organic compound was digested by Kjeldahl method and the evolved ammonia was absorbed in 60 mL of M/10 sulphuric acid. The unreacted acid required 20 mL of M/10 sodium hydroxide for complete neutralization. The percentage of nitrogen in the compound is:

1. 6%
2. 10%
3. 3%
4. 5%

Correct answer: 10%

Solution

The correct option is 10% because the amount of ammonia produced from the organic compound can be calculated from the neutralization of the unreacted sulfuric acid, which indicates the nitrogen content. By determining the moles of ammonia and relating it to the mass of the organic compound, the percentage of nitrogen can be accurately derived.

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