Some Basic Concepts of Chemistry - Result Question 3
####3. At $300 K$ and 1 atmospheric pressure,
$10 mL$ of a hydrocarbon required $55 mL$ of $O _2$ for complete combustion and $40 mL$ of $CO _2$ is formed. The formula of the hydrocarbon is
(2019 Main, 10 April I)
(a) $C _4 H _7 Cl$
(b) $C _4 H _6$
(c) $C _4 H _{10}$
(d) $C _4 H _8$
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Solution:
- In eudiometry,
Given, (i) $V _{CO _2}=10 x=40 mL \Rightarrow x=4$
(ii) $V _{O _2}=10\left(x+\frac{y}{4}\right) mL=55 mL$
$$ \begin{array}{ll} \Rightarrow & 10\left(4+\frac{y}{4}\right)=55 \ \Rightarrow & 40+\frac{y \times 10}{4}=55 \ \Rightarrow & y \times \frac{10}{4}=15 \Rightarrow y=15 \times \frac{4}{10}=6 \end{array} $$
So, the hydrocarbon $\left(C _x H _y\right)$ is $C _4 H _6$.
