Question 8 of 190
For a diatomic gas, if for rigid molecules and for another diatomic molecules, but also having vibrational modes. Then, which one of the following options is correct ? (Cp and Cv are specific heats of the gas at constant pressure and volume)
Show answer and solution
Answer: (C)
For rigid diatomic molecules
$\begin{array}{ll}
& f=5 \\
\therefore & \gamma_1=\frac{7}{5}=1.4
\end{array}$
For non-rigid diatomic molecules
$\begin{array}{ll}
& f=5+2=7 \\
& \gamma_2=\frac{9}{7}=1.28 \\
\therefore & \gamma_1\gt \gamma_2
\end{array}$
$\begin{array}{ll}
& f=5 \\
\therefore & \gamma_1=\frac{7}{5}=1.4
\end{array}$
For non-rigid diatomic molecules
$\begin{array}{ll}
& f=5+2=7 \\
& \gamma_2=\frac{9}{7}=1.28 \\
\therefore & \gamma_1\gt \gamma_2
\end{array}$