For the estimation of nitrogen, 1.4 g of an organic compound was digested by Kjeldahl method and the evolved ammonia was absorbed in 60 mL of (M)/(10) sulphuric acid. The unreacted acid required 20 mL of (M)/(10) sodium hydroxide of complete neutralization. The percentage of nitrogen in the compound is:

For the estimation of nitrogen, 1.4 g of an organic compound was diges

1.	For the estimation of nitrogen, 1.4 g of an organic compound was digested by Kjeldahl method and the evolved ammonia was absorbed in 60 mL of (M)/(10) sulphuric acid. The unreacted acid required 20 mL of (M)/(10) sodium hydroxide of complete neutralization. The percentage of nitrogen in the compound is:
Answer» `6%` `10%` `3%` `5%` Solution :Mass of organic compound `= 1.4 g` let it contain `x m` mole of `N` atom. organic compound `rarr NH_(3)` `2NH_(3)+ underset("initial taken.")underset(6 "mmole")(H_(2)SO_(4)) rarr (NH_(4))_(2)SO_(4).(1st)` `H_(2)SO_(4)underset("reacted")underset("2 mmole")(+2NaPH) rarr Na_(2)SO_(4)+2H_(2) (2nd)` Hence `m` moles of `H_(2)SO_(4)` reacted in `2nd` equation `=1` `rArr m` moles of `H_(2)SO_(4)` reatced from `1st` equation `= 6-1 = 5m` moles `rArr m` moles of `NH_(3)` in `1st` equation `= 2 xx 5 = 10 m` moles `rArr m` moles of `N` atom in the organic compound `= 10 m` moles `rArr %` of `N = (0.14)/(1.4) xx 100 = 10%`