Question

$0.2 \,g$ of an organic compound contains $C, H$ and $O$. On combustion, it yields $0.15 \,g$ $CO_{2}$ and $0.12\, g\, H_{2}O$. The percentage of $C, H$ and $O$ respectively is

• A. $C=15\%, H=20\%, O = 65\%$
• B. $C = 10\%, H = 8.2\%, O = 81.8\%$
• C. $C = 12.2\%, H=8.8\%, O = 79\%$
• D. $C = 20\%, H = 6.66\%, O = 73.34 \%$

Answer 1

Answer: (D)

$\%$ of $C=\frac{12}{44}\times\frac{0.15}{0.2}\times100=20\%$
$\%$ of $H= \frac{2}{18}\times\frac{0.12}{0.2}\times100=6.66\%$
$\%$ of $O=100-\left(20+6.66\right)=73.34\%$