For an ideal gas of diatomic molecules,which of the following relations is correct?

The ratio of the specific heats $\frac{C_p}{C_v} = \gamma$ in terms of degrees of freedom $(n)$ is given by

For a certain gas,the ratio of specific heats is given to be $\gamma = 1.5$. For this gas,

If $\frac{R}{C_v} = 0.67$,identify the gas.

For hydrogen gas,$C_P - C_V = a$,and for oxygen gas,$C_P - C_V = b$. The relationship between $a$ and $b$ is given by: (where $C_P$ and $C_V$ are molar specific heats at constant pressure and constant volume,respectively.)

Identify the correct relationship between the molar heat capacities of an ideal gas.