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What is the mass percentage of nitrogen in histamine (molecular formula C5H9N3)?

1. 25.2 %
2. 31.5 %
3. 37.8 %
4. 42.4 %

Correct answer: 37.8 %

Solution

Histamine C5H9N3 has molar mass 111.2 g/mol; the three N atoms contribute 42.03 g, giving %N = 37.8 %.

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