If for a gas $\frac{R}{C_V} = 0.67$,then the gas is .......

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

For a gas,the value of $\frac{R}{C_v} = 0.4$. What is the nature of the gas? ($R$ is the universal gas constant)

$A$ cylinder of fixed capacity $67.2 \text{ litres}$ contains helium gas at $STP$. The amount of heat needed to raise the temperature of the gas in the cylinder by $20^{\circ} C$ is: (in $\text{ J}$)

$70 \, cal$ of heat are required to raise the temperature of $2 \, moles$ of an ideal gas at constant pressure from $30^{\circ}C$ to $35^{\circ}C$. The amount of heat required to raise the temperature of the same gas through the same range ($30^{\circ}C$ to $35^{\circ}C$) at constant volume is ..... $cal$ $(R = 2 \, cal/mol \cdot K)$.

To increase the temperature of $1$ mole of an ideal monatomic gas by $10^{\circ}C$ at constant pressure,$40 \, cal$ of heat is required. How much heat (in $cal$) is required to increase the temperature by the same amount at constant volume?