0.2g of an organic compound on analysis give 0.147g of carbondioxide, 0.12 g of water and 74.6 c,c of nitrogen at S.T.P. Calculate the weight percentages of constituents.

0.2g of an organic compound on analysis give 0.147g of carbondioxide,

1.	0.2g of an organic compound on analysis give 0.147g of carbondioxide, 0.12 g of water and 74.6 c,c of nitrogen at S.T.P. Calculate the weight percentages of constituents.
Answer» Solution :Weight of COMPOUND = w = 0.2 h , volume of `N_(2)` at STP = `v_(2)` = 74.6 cc `%C = (w_(1)xx12xx100)/(wxx44) = (0.147xx12xx100)/(0.2xx44) = 20.04%` `%H = (w_(2)xx2xx100)/(wxx18) = (0.12xx2xx100)/(0.2xx18) = 6.66%` `%N = (v_(2)xx25 xx100)/(wxx22400) = (0.74.6)/(8xx0.2) = 46.63%` Weight percentage of oxygen is obtained INDIRECTLY `%O = 100 = (%C+%H+%N) = 100-73.33 = 26.67%`