On complete combustion, 0.3 g of an organic compound gave 0.2 g of $\mathrm{CO}_2$ and 0.1 g of $\ma

Question

On complete combustion, 0.3 g of an organic compound gave 0.2 g of $\mathrm{CO}_2$ and 0.1 g of $\mathrm{H}_2 \mathrm{O}$. The percentage compostion of carbon and hydrogen in the compound respectively is

Professor PC Thomas Classes · Answer

$\begin{aligned} & 	ext {  (b) : } \% 	ext { of } \mathrm{C}=\frac{12}{44} 	imes \frac{	ext { Mass of } \mathrm{CO}_2 	ext { formed }}{	ext { Mass of compound taken }} 	imes 100 \ & =\frac{12 	imes 0.2 	imes 100}{44 	imes 0.3}=18.18 \% \ & \% 	ext { of } \mathrm{H}=\frac{2}{18} 	imes \frac{	ext { Mass of } \mathrm{H}_2 \mathrm{O} 	ext { formed }}{	ext { Mass of compound taken }} 	imes 100 \ & =\frac{2 	imes 0.1 	imes 100}{18 	imes 0.3}=3.70 \%\end{aligned}$