A 30-L Sample of Helium Was Placed in a Container Fitted

Multiple Choice

A 3.0-L sample of helium was placed in a container fitted with a porous membrane. Half of the helium effused through the membrane in 24 hours. A 3.0-L sample of oxygen was placed in an identical container. How many hours will it take for half of the oxygen to effuse through the membrane?

A) 8.5 h
B) 12 h
C) 48 h
D) 60. h
E) 68 h