The complete combustion of 0.492 g of an organic compound containing 'C', 'H' and 'O' gives 0.793 g of CO2 and 0.442 g of H2O. The percentage of oxygen composition in the organic compound is ______________. (nearest integer)
Answer (integer)
46
Solution
<p>Total organic compound = 0.492 gm</p>
<p>Produced CO<sub>2</sub> = 0.793 gm</p>
<p>$\therefore$ Moles of CO<sub>2</sub> = ${{0.793} \over {44}}$</p>
<p>$\therefore$ Moles of C atoms = ${{0.793} \over {44}}$</p>
<p>$\therefore$ Weight of C atoms = ${{0.793} \over {44}}$ $\times$ 12 = 0.216 g</p>
<p>Produced H<sub>2</sub>O = 0.442 gm</p>
<p>$\therefore$ Moles of H<sub>2</sub>O = ${{0.442} \over {18}}$</p>
<p>$\therefore$ Moles of H atoms = ${{0.442} \over {18}}$</p>
<p>$\therefore$ Weight of H atoms = ${{0.442} \over {18}}$ $\times$ 2 = 0.05 g</p>
<p>$\therefore$ Weight of O atoms</p>
<p>= 0.492 $-$ (0.216 + 0.05)</p>
<p>= 0.226 gm</p>
<p>% by mass of oxygen in compound</p>
<p>= ${{0.226} \over {0.492}}$ $\times$ 100 = 46%</p>
About this question
Subject: Chemistry · Chapter: Some Basic Concepts of Chemistry · Topic: Mole Concept
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