Question

Gas A has molecules with small mass. Gas B has molecules with larger mass. They are at the same temperature.

How do the gases compare with respect to the average translational kinetic energy?
a)A has a larger average kinetic energy.b)B has a larger average kinetic energy.c)The gases have the same average kinetic energy.

Answer 1

c)The gases have the same average kinetic energy.

Step-by-step explanation:

As we know that the kinetic energy of gas is given as

`K = (1)/(2)mv^2`

here we know that

`v = \sqrt{(3RT)/(M)}`

so we have

`K = (1)/(2)m ((3RT)/(M))`

now we have

`K = (3)/(2)n RT`

now mean kinetic energy per molecule is given as

`K_(avg) = (3)/(2)KT`

so this is independent of the mass of the gas

so average kinetic energy will remain same for both the gas molecules