Posted by Kayla on .
how would you set this problem up?
An unknown gas effusees at .850 times the effusion rate of nitrogen dioxide, NO2. Estimate the molar mass of the unknown gas.

chem 
DrBob222,
rate1/rate2 = sqrt[M2/M2]
I would arbitrarily pick a number, say 10 cc/min, for the effusion rate of NO2. Then 850*10 = the rate for the unknown gas. Substitute into the above equation and solve for M2.