In Dumas' method for estimation of nitrogen 0.4 g of an organic compound gave 60 mL of nitrogen collected at 300 K temperature and 715 mm Hg pressure. The percentage composition of nitrogen in the com

Question

In Dumas' method for estimation of nitrogen 0.4 g of an organic compound gave 60 mL of nitrogen collected at 300 K temperature and 715 mm Hg pressure. The percentage composition of nitrogen in the compound is (Given: Aqueous tension at $300 \mathrm{~K}=15 \mathrm{~mm} \mathrm{Hg}$ )

Canvas Classes · Accepted Answer

Step 1: Dumas' Method — Correct for Water Vapour

The  gas is collected over water, so total pressure =  + aqueous tension.

Step 2: Convert Volume to STP

Given:  mL,  K,  mm Hg

STP:  K,  mm Hg

Step 3: Calculate Mass of Nitrogen

At STP, 22400 mL of  = 28 g (molar mass of )

Mass of nitrogen atoms (N): Since  contains 2 nitrogen atoms:

(The 28 g/mol already accounts for both atoms; the mass of N = mass of )

Step 4: Calculate Percentage of Nitrogen

Mass of compound = 0.4 g

Wait —

More questions from Practical Organic Chemistry