0.30 gm of an organic compound gave 50 ml of nitrogen collected at 300 K and 715 mm pressure in dumas method. Calculate the percentage of nitrogen in the compound. (Vapour pressure of water or aqueous tension of water at 300 K is 15 mm.)

Options

A. 0.2238
B. 0.1746
C. 0.5511
D. 0.8274

Answer

B

Explanation

Volume of nitrogen collected at 300 K and 715 mm pressure is 50 mL
Actual pressure =715-15=700 mm
Volume of nitrogen at STP `(273xx700xx50)/(300xx760) =41.9 mL`
22,400 mL of `N_(2)` at STP weight =28 g
41.9 mL of nitrogen weight =(28xx41.9)/22400 g`
Percentage of nitrogen `=(28xx41.9xx100)/(22400xx0.3) =17.46%`