Q88 / 200 · NEET 2024 (Re-NEET) · Chemistry
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 composition of carbon and hydrogen in the compound, respectively is:
- A$4.07 \%$ and $15.02 \%$
- Correct answerB$18.18 \%$ and $3.70 \%$
- C$15.02 \%$ and $4.07 \%$
- D$3.70 \%$ and $18.18 \%$
Solution
Percentage of carbon $=\frac{12 \times \mathrm{m}_2 \times 100}{44 \times \mathrm{m}}$
$\mathrm{m}=$ mass of organic compound $=0.3 \mathrm{~g}$
$\mathrm{m}_2=$ mass of carbon dioxilde $=0.2 \mathrm{~g}$
$\therefore \% C=\frac{12 \times 0.2 \times 100}{44 \times 0.3}=18.18 \%$
Percentage of hydrogen $=\frac{2 \times \mathrm{m}_1 \times 100}{18 \times \mathrm{m}}$
$\mathrm{m}_1=$ mass of water $=0.1 \mathrm{~g}$
$\therefore \% \mathrm{H}=\frac{2 \times 0.1 \times 100}{18 \times 0.3}=3.70 \%$
Hence, the correct answer is option: 'B'.