In Dumas’ method for estimation of nitrogen, 0.3g of an organic compound gave 50mL of nitrogen collected at 300K temperature and 715mm pressure. Calculate the percentage composition of nitrogen in the compound. (Aqueous tension at 300K=15 mm)

Explanation

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