0.35 g of an organic susbtance was Kjeldahilsed and the ammonia obtained was passed into 100ml of M/`10H_(2)SO_(4)` The excess acid required 154 ml of `M//10 NaOH` for neurtralisation, calculate the % of nitrogen in the compound.

Explanation

Volume of `M/10 H_(2)SO_(4)` taken = 100ml
Excess volume of `M/10 H_(2)SO_(4)` is
Excess volume of `M/10 H_(2)SO_(4)` is
154 ml of `M/10 NaOH = 154/2` ml of `M/10 H_(2)SO_(4)`
`:.` Volume of `H_(2)SO_(4)` left unused = 77ml
Volume of `M/10 H_(2)SO_(4)` used for neutrilisation of `NH_(3)=100-77=23ml`
Now , 23ml of `M/10 H_(2)SO_(4) = 2xx23` ml of `M/10 NH_(3)`
= 46 ml of `M/10 NH_(3)` now, 1000 ml of 1 M `NH_(3)` contains 14g N
`:.` 46 ml of `M/10 NH_(3)` contains `14/1000 xx(46xx1)/10`
% of `N=(14xx46xx100)/(1000xx10xx0.35)=18.4%`