States of Matter - Result Question 94
####94. $3.7 g$ of a gas at $25^{\circ} C$ occupied the same volume as $0.184 g$ of hydrogen at $17^{\circ} C$ and at the same pressure. What is the molecular weight of the gas?
$(1979,2 M)$
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Solution:
- For same $p$ and $V, n \propto \frac{1}{T}$
$$ \begin{array}{ll} \Rightarrow & \frac{n(gas)}{n\left(H _2\right)}=\frac{T\left(H _2\right)}{T(gas)} \ \Rightarrow & n\left(H _2\right)=\frac{0.184}{2}=0.092 \ & n(gas)=\frac{290}{298} \times 0.092=0.0895 \end{array} $$
$\because \quad 0.0895$ mole of gas weigh $3.7 g$
$\therefore 1$ mole of gas will weigh $\frac{3.7}{0.0895}=41.32 g$
