Question

If 0.2g of an organic compound containing carbon, hydrogen and oxygen on combustion, yielded 0.147g carbon dioxide and 0.12g water. What will be the content of oxygen in the substance?

• A. $73.29$ %
• B. $78.45$ %
• C. $83.23$ %
• D. $89.50$ %

Answer 1

The correct option is A $73.29$ %

%$C=\frac{12}{44}\times \frac{massofc{o}_2}{massofcompd.}\times 100$
$=\frac{12}{44}\times \frac{0.147}{0.2}\times 100$
$c=20.04$%
%$H=\frac{2}{18}\times \frac{massof{H}_{2}O}{massofcompel}\times 100$
$=\frac{2}{18}\times \frac{0.12}{0.2}\times 100$
$H=6.66$%
% $0=100-$(% g c+% of H)
$=100-(20.04+6.66)$
$=100-26.70$
%$\therefore 0=73.29$ %