For all gases,$C_P - C_V$ is a constant. Does this imply that for all gases,$\frac{C_P}{C_V}$ is also a constant?

The specific heat of helium at constant volume is $12.6 \,J \,mol^{-1} \,K^{-1}$. The specific heat of helium at constant pressure in $J \,mol^{-1} \,K^{-1}$ is approximately (assume, the universal gas constant, $R=8.314 \,J \,mol^{-1} \,K^{-1}$)

If a gas has $f$ degrees of freedom,what is the ratio ${C_p}/{C_v}$?

The value of the gas constant $(R)$ calculated from the perfect gas equation is $8.32 \ J/mol \cdot K$,whereas its value calculated from the knowledge of $C_P$ and $C_V$ of the gas is $1.98 \ cal/mol \cdot K$. From this data,the value of $J$ is ......... $J/cal$.

$A$ cylinder of fixed capacity of $44.8 \, L$ contains helium gas at standard temperature and pressure. The amount of heat needed to raise the temperature of the gas in the cylinder by $20.0^{\circ} C$ will be .............. $J$ (Given gas constant $R = 8.3 \, J \, K^{-1} \, mol^{-1}$).

Write the value of $\gamma$ for a polyatomic gas.