29.5 mg of an organic compound containing nitrogen was digested according to Kjeldahl's method and the evolved ammonia was absorbed in 20 mL of 0.1M HCl solution. The excess of the acid required 15 mL of 0.1 M NaOH solution for complete neutralization. The percentage of nitrogen in the compound is (A) 59.0 (B) 47.4 (C) 23.7 (D) 29.5

Moles of HCl reacting with ammonia = (moles of HCl absorbed) – (moles of NaOH solution required)

= (20 x 0.1 x 10-3) – (15 x 0.1 x 10-3)

= Moles of NH3 evolved

= Moles of nitrogen in organic compound

Hence,

Weight of nitrogen in organic compound = 0.5 x 10-3 x 14

We get,

= 7 x 10-3 g

% of nitrogen = (7 x 10-3)/(29.5 x 10-3) x 100

We get,

= 23.7%

Therefore, the percentage of nitrogen in the compound is 23.7%

So, the correct option is (C)

Was this answer helpful?

 
   

0 (0)

(0)
(0)

Choose An Option That Best Describes Your Problem

Thank you. Your Feedback will Help us Serve you better.

Leave a Comment

Your Mobile number and Email id will not be published. Required fields are marked *

*

*

BOOK

Free Class

Ask
Question