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

`w=0.30g V_(1)=50ml`
`P_(1)=(P-a)=715-15=700mm` of Hg
`T_(1)=300K`
Now, `(P_(1)V_(1))/(T_(2))=(P_(2)V_(2))/(T_(2))`
`rArr V_(2)=(P_(1)V_(1)xxT_(2))/(T_(1)xxP_(2))=(273xx700xx50)/(300xx760)`
`V_(2)=41.9`ml
Wt. of nitrogen `=(28)/(22400)xx41.9g`
Percentage of Nitrogen `=(28xx41.9)/(22400xx0.3)xx100=17.46`