In Kjeldahl method, 1 g compound neutralizes 15 mL of 1 M H₂SO₄. Find percentage of nitrogen.

Solution:

Volume of H₂SO₄ = 15 mL = 0.015 L

Moles of H₂SO₄:

= M × V

= 1 × 0.015

= 0.015 mol

1 mole of H₂SO₄ neutralizes 2 moles of NH₃.

Moles of NH₃:

= 2 × 0.015

= 0.03 mol

Mass of nitrogen:

= 0.03 × 14

= 0.42 g

Percentage of nitrogen:

= (0.42 / 1) × 100

= 42%

Answer: 42%