# A polyatomic ideal gas

Question:

A polyatomic ideal gas has 24 vibrational modes. What is the value of $\gamma$ ?

1. 1.03

2. 1.30

3. 1.37

4. 10.3

Correct Option: 1

Solution:

Since each vibrational mode has 2 degrees of freedom hence total vibrational degrees of freedom $=48$

$f=3+3+48=54$

$\gamma=1+\frac{2}{f}=\frac{28}{27}=1.03$