Question

The ratio C_p / C_v for a gas is 1.29. What is the degree of freedom of the molecules of this gas?

Answer 1

For the molecules of a gas, `gamma = ("C"_"P")/("C"_"V") = 1+ 2/"f" `

where f is the degree of freedom.

Given : γ =1.29 

`=> 1+2/"f" = 1.29 = 9/7`

`=> 2/"f" =9/7 -1`

`=> 2/"f" =2/7`

⇒ f =7

Therefore, the molecules of this gas have 7 degrees of freedom.
But in reality, no gas can have more than 6 degrees of freedom.