Answer:
Ratio is 4:1
Explanation:
from graham's law of gaseous diffusion:
[tex]{ \bf{ \frac{R _{A} }{R_{B} } = \sqrt{ \frac{M_{A} }{M_{B}} } }}[/tex]
but Ra = 2Rb:
[tex]{ \sf{ (\frac{2}{1} ) {}^{2} = \frac{M _{A}}{M _{B} } }} \\ \\ { \sf{\frac{M _{A}}{M _{B} } = \frac{4}{1} }} \\ \\ {M _{A}} : {M _{B} } = 4 :1[/tex]
