A samlpe of 0.5 of an organic compound was analysed using Kjeldahl' method. The ammonia evolved was absorbed in 50 ml of 0.5 M `H_(2)SO_(4)`. The unsused acid after neutralisation by ammonia consumed 80 ml of 0.5N NaOH. Then calculate percentage of nitrogen in organic compound

Answer

B

Explanation

Unused acid required = 80 mL of 0.5 M NaOH
80 mL of 0.5 M NaOH = 40 mL of 0.5 M `H_2 SO_4`
Volume of acid used = (50 - 40) mL of 0.5 M `H_2 SO_4`
= 10 mL of 0.5 M `H_2 SO_4`
`%` of Nitrogen `= (1.4 xx "Molarity of acid" xx "Basicity" xx "Vol. of acid used")/("Mass of compound taken")`
`= (1.4 xx 0.5 xx 2 xx 10)/( 0.5 ) = 28`