In Dumas' method of estimation of nitrogen `0.35 g` of an organic compound gave `55mL` of nitrogen collected at `300K` temperature and `715 mm` pressure. The percentage composition of nitrogen in the compound would be `: (` Aqueous tension at `300K =15 mm)`

Options

A. 14.45
B. 15.45
C. 16.45
D. 17.45

Answer

C

Explanation

`P_(1) = 715-15 = 700 mm, V_(1) = 55 mL, T_(1) = 300 K`
`P_(2) = 760 mm, T_(2) = 273 K, V_(2) = ?`
`(P_(1)V_(1))/T_(1) = (P_(2)V_(2))/T_(2)`
`V_(2) = (P_(1)V_(1)T_(2))/(P_(2)T_(1)) = (700 xx 55 xx 273)/(760 xx 300)`
= 46.1 mL
`%N = 28/22400 xx (46.1)/0.35 xx 100`
`=16.46 %`