Exactly of an organic soil sample was digested using Kjeldahl's protocol. The ammonia gas evolved wa — Qualitative and Quantitative Analysis Chemistry Question

💡 Solution & Explanation

$10 \text{ mL}$ of $1.0 \text{ M}$ $H_2SO_4$ is $2.0 \text{ N}$ acid, providing $10 \times 2.0 = 20$ meq of acid. Since no back-titration is needed, $NH_3$ neutralized all $20$ meq. Mass of $N = 20 \times 10^{-3} \text{ mol} \times 14 \text{ g/mol} = 0.28 \text{ g}$. Percentage = $(0.28 \text{ g} / 0.75 \text{ g}) \times 100 = 37.33\%$.