What is the value of $\frac{R}{C_P}$ for a diatomic gas?

The amount of heat needed to raise the temperature of $4 \, \text{moles}$ of a rigid diatomic gas from $0^{\circ} \text{C}$ to $50^{\circ} \text{C}$ when no work is done is ......$R$ ($R$ is the universal gas constant).

One mole of an ideal gas $\left( \frac{C_P}{C_V} = \gamma \right)$ is heated according to the law $P = \alpha V$,where $P$ is the pressure of the gas,$V$ is the volume,and $\alpha$ is a constant. What is the molar heat capacity of the gas in this process?

Select the incorrect statement about the specific heats of a gaseous system.

For an ideal non-rigid diatomic gas,the value of $\frac{R}{C_V}$ is nearly,given that $\gamma = \frac{C_P}{C_V} = \frac{9}{7}$.

What amount of heat (in $J$) must be supplied to $2.0 \times 10^{-2} \; kg$ of nitrogen (at room temperature) to raise its temperature by $45 \; ^{\circ}C$ at constant pressure? (Molecular mass of $N_{2} = 28; R = 8.3 \; J \; mol^{-1} K^{-1}$.)