12.33. A sample of 0.50 g of an organic compound was treated according to Kjeldahl’s method. The ammonia evolved was absorbed in 50 ml of 0.5 . The residual acid required 60 mL of 0.5 M solution of for neutralisation. Find the percentage composition of nitrogen in the compound.
Given that,
total mass of organic compound = 0.50 g
60 mL of 0.5 M solution of required for neutralisation by residual acid.
60 mL of 0.5 M solution = mL of 0.5M = 30 mL of 0.5 M
Therefore,
Acid consumed in absorption of evolved ammonia is (50-30) mL = 20 mL
Again, 20 mL of 0.5 M = 40 mL of 0.5 M
Also, since 1000 mL of 1 M contains 14 g of nitrogen,
So, 40 mL of 0.5 M will contain = g of Nitrogen
Therefore, percentage(%) of nitrogen in 0.50 g of organic compound = = 56 %