it takes a certain gas 1.98 times as long to diffuse as an equal volume of helium under the same conditions. what is the calculated molecular weight of the gas?

Answer 1

Isn't this Graham's law of diffusion

rate1/rate2 = sqrt(mass2)/sqrt(mass1)

1.98= sqrt (mass1/4)

square both sides, multiply both sides by 4.

In my head, it is about 16

Answer 2

Core of Graham's law of diffusion

r¹/r²=√(M²/M¹ )

2.3=√(M¹/32)

Sq. both sides & multiply both side by 32

My head dictates it 169