0.25 g of an organic compound โAโ containing carbon, hydrogen and oxygen was analysed using the comb โ JEE Mains Chemistry Past Papers Chemistry Question
Question
0.25 g of an organic compound โAโ containing carbon, hydrogen and oxygen was analysed using the combustion method. There was an increase in mass of CaCl2 tube and potash tube at the end of the experiment. The amount was found to be 0.15 g and 0.1837 g, respectively. The percentage of oxygen in compound A is ________%. (Nearest integer) (Given : molar mass in g mol โ1 H : 1, C : 12, O : 16)
๐ก Solution & Explanation
CxHyOz + O2 ๏ฎ CO2 + H2O t = 0 0.25 gm teq โ 0.18 gm 0.15 gm Mass of โCโ = 0.18 44 ร 12 = 0.049 0.05 gm Mass of โHโ = 0.15 18 ร 2 = 0.016 0.017 gm. Mass of โOโ = 0.25 โ 0.05 โ 0.017 = 0.1833 gm Mass % of โOโ = 0.1833 0.25 ร 100 = 73.32%.