In Dumas method for estimation of nitrogen, 0.50 g of an organic compound gave 70 mL of nitrogen collected at 300 K and 715 mm pressure. The percentage of nitrogen in the organic compound is %. (Aqueous tension at 300 K is 15 mm).
Answer
15
Solution
Pressure of dry N2 = 715 - 15 = 700 mm
Volume at STP: V0 = p1V1T1 T0p0
V0 = 700 70300 273760 = 58.67 mL
Mass of N2 = 28 58.6722400 = 0.0733 g
% of N = 0.07330.50 100 = 14.67\% 15\%
Answer: 15