JEE Main 2024 · Chemistry · Qualitative and Practical Chemistry · easy

In a Kjeldahl estimation, the ammonia from 0.280 g of an organic compound was absorbed in 50.0 mL of 0.200 N H2SO4. The excess acid required 32.0 mL…

Numerical answer

In a Kjeldahl estimation, the ammonia from

0.280\ \mathrm{g}

of an organic compound was absorbed in

50.0\ \mathrm{mL}

0.200\ \mathrm{N}

\mathrm{H_2SO_4}

. The excess acid required

32.0\ \mathrm{mL}

0.100\ \mathrm{N}

NaOH for neutralisation. The percentage of nitrogen in the compound (N = 14) is

Show answer and solution

Answer: 34

Total acid

=50.0\times0.200=10.0

meq; excess neutralised by NaOH

=32.0\times0.100=3.20

meq. Acid used by

\mathrm{NH_3}

=10.0-3.2=6.8

meq, equal to

6.8

mmol of N. Mass of N

=6.8\times14=95.2\ \mathrm{mg}

. Percentage

=95.2/280\times100=34.0\%

Original question written in the JEE Main 2024 pattern and checked twice for the correct answer. Not an official question paper. How we write and check questions · Corrections policy · Report a mistake