$A$ 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 $\text{ J}$)

The amount of heat that must be supplied to $35 \ g$ of oxygen at room temperature to raise its temperature by $80^{\circ} C$ at constant volume is (molecular mass of oxygen is $32$ and $R = 8.3 \ J \ mol^{-1} \ K^{-1}$) (in $kJ$)

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

$Assertion :$ The ratio of $\frac{C_p}{C_v}$ for an ideal diatomic gas is less than that for an ideal monoatomic gas (where $C_p$ and $C_v$ have usual meaning).
$Reason :$ The atoms of a monoatomic gas have less degrees of freedom as compared to molecules of the diatomic gas.

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?

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