A sample of 0 . 125 g of an organic compound when analysed by Duma's method yields 22 . 78 mL of nitrogen gas collected over KOH solution at 280 K and 759 mmHg . The percentage of nitrogen in the given organic compound is____ (a) The vapour pressure of water at 280 K is 14 . 2 mmHg (b) R = 0 . 082 L atm K - 1 mol - 1

Step-by-step solution

Let the mass of organic compound = m g Volume of nitrogen collected = V 1 mL Room temperature = T 1 K V = 22 . 78 ml , T = 280   K P total = 759 mmHg P N 2 = Atmospheric pressure – Aqueous tension P N 2 = 759 - 14 . 2 = 744 . 8 mmHg 22400   mL   N 2   at   STP   weighs   28   g . V   mL   N 2   gas   at   STP   weighs   =   28 × V 22400 g n N z = 744 . 8 × 22 . 78 760 × 1000 × 0 . 082 × 280 = 0 . 00097 W N