On complete combustion, 0.246g of an organic compound gave 0.198 g of carbon dioxide and 0.1014 g of water. Determine the percentage composition of carbon and hydrogen in the compound.

On complete combustion, 0.246g of an organic compound gave 0.198 g of

1.	On complete combustion, 0.246g of an organic compound gave 0.198 g of carbon dioxide and 0.1014 g of water. Determine the percentage composition of carbon and hydrogen in the compound.
Answer» Solution :Here, mass of the organic substance taken = 0.246 g Mass of `CO_(2)` FORMED = 0.198 g Mass of `H_(2)O` formed = 0.1014 g (i) Percentage of Carbon. One mole of `CO_(2)` contains one gram atom of carbon. i.e. 44 g of `CO_(2)` contain carbon = 12g `:.` 0.198 g `CO_(2)` will contain carbon `= (12)/(44) XX 0.198 g` This is the mass of carbon present in 0.246 g of the compound. `:.` % age of carbon in the compound `= (12)/(44) xx 0.198 xx (100)/(0.246) = 21.95` (II) Percentage of Hydrogen One mole of `H_(2)O` contains two gram atoms of hydrogen. i.e. 18G of `H_(2)O` contain hydrogen = 2g `:.` 0.1014 g of `H_(2)O` will contain hydrogen `= (2)/(18) xx 0.1014` This is the mass of hydrogen present in 0.246g of the compound. `:.` % age of hydrogen in the compound `= (2)/(18) xx 0.1014 xx (100)/(0.246) = 4.58`