The quantity of heat required to raise the temperature of one mole of a monoatomic gas by one degree Kelvin at constant volume is

Molar specific heat of oxygen at constant pressure $C_p = 7.2 \, cal/mol \cdot ^\circ C$ and $R = 8.3 \, J/mol \cdot K$. At constant volume,$5 \, mol$ of oxygen is heated from $10^\circ C$ to $20^\circ C$. The quantity of heat required is approximately ........ $cal$.

$Assertion :$ 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.

Which of the following statements is correct?

$Assertion:$ At a given temperature,the specific heat of a gas at constant pressure $(C_p)$ is always greater than its specific heat at constant volume $(C_v)$.
$Reason:$ When a gas is heated at constant volume,some extra heat is needed compared to that at constant pressure for doing work in expansion.

$C_v$ and $C_p$ denote the molar specific heat capacities of a gas at constant volume and constant pressure,respectively. Then