While estimating the nitrogen present in an organic compound by Kjeldahl's method, the ammonia evolv — Practical Organic Chemistry and Purification Chemistry Question

💡 Solution & Explanation

**Step 1: Determine moles of H₂SO₄** Moles of H₂SO₄ = Molarity × Volume (L) Moles of H₂SO₄ = 2 M × 0.0025 L = 0.005 mol **Step 2: Determine moles of NH₃ using stoichiometry** The neutralization reaction is: 2NH₃ + H₂SO₄ → (NH₄)₂SO₄ From the equation: 1 mol H₂SO₄ neutralizes 2 mol NH₃ Moles of NH₃ = 2 × 0.005 = 0.01 mol **Step 3: Determine moles of nitrogen** Each NH₃ molecule contains 1 nitrogen atom Moles of N = 0.01 mol **Step 4: Calculate mass of nitrogen** Atomic mass of N = 14 g/mol Mass of N = 0.01 mol × 14 g/mol = 0.14 g **Step 5: Calculate percentage of nitrogen** Percentage of N = (Mass of N / Mass of compound) × 100 Percentage of N = (0.14 g / 0.25 g) × 100 = 56% Therefore, the answer is 56.