When a hydrocarbon A undergoes complete combustion it requires 11 equivalents of oxygen and produces 4 equivalents of water. What is the molecular formula of $A$ ?
Solution
$$
\begin{aligned}
& \mathrm{C}_{\mathrm{x}} \mathrm{H}_{\mathrm{y}}+\left(\mathrm{x}+\frac{\mathrm{y}}{4}\right) \mathrm{O}_2 \rightarrow \mathrm{xCO}_2+\frac{\mathrm{y}}{2} \mathrm{H}_2 \mathrm{O} \\\\
& \frac{\mathrm{y}}{2}=4 \Rightarrow \mathrm{y}=8 \\\\
& \mathrm{x}+\frac{8}{4}=11 \\\\
& \Rightarrow \mathrm{x}=9 \\\\
& \therefore \text { Hydrocarbon will be }=\mathrm{C}_9 \mathrm{H}_8
\end{aligned}
$$
About this question
Subject: Chemistry · Chapter: Some Basic Concepts of Chemistry · Topic: Mole Concept
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