What is the kinetic energy of $1$ mole of a monatomic gas?

If the mass of each molecule of a gas kept at a constant pressure $P$ in a container is halved and their speed is doubled,what will be the resulting pressure of the gas?

$A$ flask contains Hydrogen and Argon in the ratio $2:1$ by mass. The temperature of the mixture is $30^{\circ} C$. The ratio of average kinetic energy per molecule of the two gases $(K_{\text{argon}} / K_{\text{hydrogen}})$ is: (Given: Atomic weight of $Ar = 39.9$)

The average translational kinetic energy of a hydrogen gas molecule at $NTP$ will be. [Boltzmann's constant $k_B = 1.38 \times 10^{-23} \text{ J/K}$]

The temperature at which the kinetic energy of oxygen molecules becomes double its value at $27^{\circ}\,C$ is $............^{\circ}\,C$.

The average kinetic energy of a monatomic molecule is $0.414 eV$ at temperature : (Use $K_{B} = 1.38 \times 10^{-23} J/K$) (in $K$)