On complete combustion 0.30 g of an organic compound gave 0.20 g of carbon dioxide and 0.10 g of water. The percentage of carbon in the given organic compound is _____________. (Nearest integer)
Answer (integer)
18
Solution
<p>$${C_x}{H_y} + \left( {x + {y \over 4}} \right){O_2} \to x\,C{O_2} + {y \over 2}{H_2}O$$</p>
<p>Given organic compound C<sub>x</sub>H<sub>y</sub>= 0.3 gm</p>
<p>Produced carbon dioxide (CO<sub>2</sub>) = 0.2 gm</p>
<p>Produced water (H<sub>2</sub>O) = 0.1 gm</p>
<p>Moles of CO<sub>2</sub> = ${{0.2} \over {44}}$</p>
<p>$\therefore$ Moles of C atom = ${{0.2} \over {44}}$</p>
<p>$\therefore$ Mass of C atom = ${{0.2} \over {44}}$ $\times$ 12 = 0.0545</p>
<p>Moles of H<sub>2</sub>O = ${{0.1} \over {18}}$</p>
<p>$\therefore$ Moles of H atoms = ${{0.1} \over {18}}$ $\times$ 2</p>
<p>$\therefore$ Mass of H atoms = ${{0.1} \times2\over {18}}$ $\times$ 1 = 0.0111</p>
<p>$\therefore$ % of C atom = ${{0.0545} \over {0.3}}$ $\times$ 100 = 18%</p>
About this question
Subject: Chemistry · Chapter: Some Basic Concepts of Chemistry · Topic: Mole Concept
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