Question

The fraction of molecular volume to the actual volume occupied by oxygen gas at STP. (Take the diameter of an oxygen molecule to be $3A^{\circ }$)

• A. $3.8\times {10}^{-4}$
• B. $7.6\times {10}^{-4}$
• C. $1.9\times {10}^{-4}$
• D. $2.4\times {10}^{-4}$

Answer 1

The correct option is A $3.8\times {10}^{-4}$

$\begin{array}{c}\begin{array}{cc}\text{diameter}& =3A^{\circ }\\ & \Rightarrow \text{radius}=1.5\times {10}^{-8}cm\end{array}\\ \text{molecular volume}V=\frac{4}{3}\pi r^{3}N\end{array}$

$=8.52cc$

$\begin{array}{c}\text{Let}{v}^{\prime }\text{be actual volume occupied by}1\text{mole}{O}_2\text{at}STP\\ =22400cc\\ \therefore \frac{V}{V1}=\frac{8.52}{22400}=3.8\times {10}^{-4}\end{array}$