Question

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

• A. $\%C-21.95,\%H-4.58$
• B. $\%C-21.95,\%H-5.58$
• C. $\%C-11.95,\%H-5.58$
• D. $\%C-11.95,\%H-4.58$

Answer 1

Answer: (A)

Given mass of $C{O}_2=0.198g$ and mass of $H_{2}O=0.1014g$
As we know, $\%$ of $C=\frac{12}{44}\times \frac{m_{C{O}_2}}{w}\times 100$
Percentage of carbon $=\frac{12\times 0.198\times 100}{44\times 0.246}=21.95\%$
Also,$H=\frac{2}{18}\times \frac{m_{H_{2}O}}{w}\times 100$
Percentage of hydrogen $=\frac{2\times 0.1014\times 100}{18\times 0.246}=4.58\%$