The mean kinetic energy of a gas at $300\, K$ is $100\, J.$ The mean energy of the gas at $450\, K$ is equal to ...... $J$

If $E$ is the kinetic energy per mole of an ideal gas and $T$ is the absolute temperature,then the universal gas constant is given as

By using which equation can the force acting on the walls of a container due to gas molecules be obtained?

Define temperature in view of kinetic energy of a gas.

Number of molecules in a volume of $4\, cm^{3}$ of a perfect monoatomic gas at some temperature $T$ and at a pressure of $2\, cm$ of mercury is close to $?$
(Given,mean kinetic energy of a molecule (at $T$) is $4 \times 10^{-14}\, erg$,$g=980\, cm/s^{2}$,density of mercury $=13.6\, g/cm^{3}$)

$1\, kg$ of a diatomic gas is at a pressure of $8 \times 10^4\, N/m^2$. The density of the gas is $4\, kg/m^3$. What is the energy of the gas due to its thermal motion?