What is the ratio of specific heats at constant pressure and constant volume for $NH_3$?

When an ideal diatomic gas is heated at constant pressure,the fraction of the heat utilized to increase the internal energy of the gas is

$5 \ \text{moles}$ of an unknown gas is heated at constant volume from $10^\circ \text{C}$ to $20^\circ \text{C}$. The molar specific heat of this gas at constant pressure is $c_p = 8 \ \text{cal/mol} \cdot ^\circ \text{C}$ and the gas constant is $R = 8.36 \ \text{J/mol} \cdot ^\circ \text{C}$. The change in the internal energy of the gas is . . . . . . calorie.

The specific heat at constant volume for the monoatomic argon is $0.075 \, kcal/kg-K$,whereas its gram molecular specific heat $C_V = 2.98 \, cal/mole/K$. The mass of the argon atom is (Avogadro's number $= 6.02 \times 10^{23} \, molecules/mole$)

For a gas,$\frac{R}{C_{V}} = 0.4$,where $R$ is the universal gas constant and $C_{V}$ is the molar specific heat at constant volume. The gas is made up of molecules which are

The specific heat of a gas: