Question

If 3.7 $g$ of a gas at ${25}^{\circ }C$ occupies the same volume as 0.184 $g$ of hydrogen at 1$7^{\circ }C$ and at the same pressure, then what is the molecular mass no. of the gas?

Answer 1

According to ideal gas equation,
$PV=nRT$
$P$ and $V$ are the same.
So, $n_1{T}_1=n{T}_2$
or $\frac{w_1}{M_1}=\frac{w_2}{M_2}{T}_2$
or $\frac{3.7}{M_1}\times 298=\frac{0.184}{2}\times 290$
$M_1=41.33g$
Molecular mass no is 41.