1.216 gm of an organic compound was reacted under Kjeldahl's method and the ammonia evolved was absorbed in 100 ml `NH_2SO_4`. The remaining acid solution was made up to 500 ml by the addition of water. Twenty millilitres of the dilute solution required 32 ml `(N)/(10)` caustic soda solution for complete neutralisation. Calculate the percentage of nitrogen in the compound.

Explanation

20 ml dilute unreacted acid solution required
`=32ml(N)/(10)NaOH` solution
500 ml dilute unreacted acid solution required
`=(32)/(20)xx500ml(N)/(10)NaOH` solution
`=(32)/(20)xx(500)/(10)" ml "N NaOH`
`=80ml N NaOH`
`80"ml "N" NaOH"=80ml" N "H_2SO_4`
Acid used for the neutralisation of `NH_3`
`=(100-80)" ml N "H_2SO_4`
`=20" ml N "H_2SO_4`
Percentage of nitrogen `=1.4xxN_1xx(V)/(W)`
`N_1=1,V=20" ml"` and `W=1.216 gm`
So the percentage of nitrogen `=(1.4xx1xx20)/(1.216)=23.03`