Question

Gas A diffuses 2 times faster than gas B. Ratio of their molecular weights is:

Answer 1

Assign some values just to make the problem easier to solve; i.e., let rate for gas B = 50 mL/hr, then rate for gas A = 100 mL/hr

(rate A/rate B) = sqrt (molar mass B/molar mass A)
(100/50) = sqrt (mm B/mm A)
2 = sqrt (mm B/mm A)
4 = molar mass B/molar mass A