In a Kjeldahl estimation, 0.750 g of an organic compound was digested and the ammonia evolved was absorbed in 40.0 mL of 0.500 M $H X_{2} SO X_{4}$ . The excess acid required 26.0 mL of 0.800 M NaOH for neutralisation. Using atomic mass N = 14, calculate the percentage of nitrogen in the compound. Give the answer to two decimal places.

Numerical answer type, answer in %, tolerance 0.02.

Answer: 35.84 %

Milliequivalents of acid taken

= 40.0 \times 0.500 \times 2 = 40.0

; of NaOH used

= 26.0 \times 0.800 = 20.8

. Acid neutralised by ammonia

= 40.0 - 20.8 = 19.2

meq, so N

= 19.2 \times 14 = 268.8

mg. Percentage N

= 268.8/750 \times 100 = 35.84