The Maxwell-Boltzmann distributions of molecular speeds in samples of two different gases at the same
temperature are shown above. Which gas has the greater molar mass?
(A) Gas A
(B) Gas B
(C) Both gases have the same molar mass.
(D) It cannot be determined unless the pressure of each sample is known.
The samples could be at different presssures which would affect the speed/velocity of the particles. Since pressure is a factor, we can't really tell the molar mass of the gases.