When 1 g of compound ( X ) is subjected to Kjeldahl's method for estimation of nitrogen, 15 mL 1 M H ₂ SO ₄ was neutralized by ammonia evolved. The percentage of nitrogen in compound ( X ) is :

Step-by-step solution

In Kjeldahl's method, nitrogen in the compound is converted to NH₃. The ammonia is absorbed and reacts with H₂SO₄ according to: 2NH₃ + H₂SO₄ (NH₄)₂SO₄ . Given that 15 mL of 1 M H₂SO₄ was neutralized: Moles of H₂SO₄ = 15 × 10⁻³ mol. From stoichiometry, 1 mol H₂SO₄ reacts with 2 mol NH₃. Therefore, moles of NH₃ = 2 × 15 × 10⁻³ = 0.030 mol. Since each NH₃ contains 1 nitrogen atom: Moles of N = 0.030 mol. Mass of N = 0.030 × 14 = 0.42 g. Percentage of N in compound = (0.42/1) × 100 = 42%.