In the estimation of nitrogen by Kjeldahl's method, 2.8 g of an organic compound required 20 millimoles of `H_(2)SO_(4)` for the complete neutralisation of `NH_(3)` gas evolved. The percentage of nitrogen in the sample is

Options

A. `20%`
B. `10%`
C. `40%`
D. `30%`

Answer

A

Explanation

`% of N=(1.4xxm" Eq of "H_(2)SO_(4) "used to neutralise" NH_(3))/("Weight of compound")`
`m" mol of "H_(2)SO_(4)=20`
`m" Eq of "H_(2)SO_(4)=20xx2=40` (n factor`=2`)
`% of N=(1.4xx40)/(2.8)=20%`