Two gases X (molecular weight MX) and Y (molecular weight MY) (MY > MX) are at the same temperature, T in two different Containers. Their root mean square velocities are CX and CY respectively. If the average kinetic energies per molecule of two gases X and Y are EX and EY respectively then which of the following relation(s) is (are) true? (WB JEE 2014)

Given, molecular weight of X X M Molecular weight of Y = MY and MY > MX Root mean square velocities = CX and CY respectively. Average KE/molecule = EX and EY respectively. We know that, Root mean square velocity, 3 1 or / / X Y Y X RT C C C C M M M M >> >> / / X Y Y X C C M M Since, Y X X Y M M C C >> KE/mole = 3 2 RT Gaseous State 31 3 3 / 2 2 B A R KE mole T k T N >> So, 3 2 X Y B E E k T