Question

In the estimation of nitrogen by Dumas method 1.18g of an organic compound gave 224 ml of $N_2$ at NTP. The percentage of nitrogen in the compound is about :

• A. $20.0\%$
• B. $11.8\%$
• C. $47.5\%$
• D. $23.72\%$

Answer 1

The correct option is D $23.72\%$

Volume of nitrogen gas obtained $=224ml$,

so mole of nitrogen gas $=\frac{224}{22400}=0.01$

(As volume of one mole of gas is 22400 ml)

mass of nitrogen gas evolved is $=\frac{224}{22400}\times 28=0.28$ gm.

So organic compound contains 0.28gm of nitrogen,

% of nitogen in compound $=\frac{0.28}{1.18}\times 100=23.72$ %

Option D is correct.