0.25g of an organic compound gave `30cm^(3)` of moist dinitrogen at 288K and 745mm pressure. Calculate the percentage of nitrogen. (Aqueous tension at 288K = 12.7mm)

Explanation

Mass of the substance = 0.25g
Volume of moist dinitrogen = `30cm^(3)`
Temperature = 288K
Pressure `= 745- 12.7 = 732.3mm`
Volume of dinitrogen at S.T.P
`V_(2) = (P_(1)V_(1))/(T_(1)) xx (T_(2))/(P_(2)) = (732.3 xx 30 xx 273)/(288 xx 760) = 27.4 cm^(3)`
`22400cm^(3)` of dinitrogen at STP weight = 28g
`27.4 cm^(3)` of dinitrogen at STP weight `= (28 xx 27.4)/(22400)`
= 0.034g
Percentage of nitrogen in organic compound `=(0.034)/(0.25) xx 100 = 13.6`