Two identical sealed 1.0L containers are filled at STP with N2 an0d SF6.

a.) Which gas has the greatest number of molecules?
b.) Which gas has the greatest density?
c.) Which has the highest average kinetic energy?
d.) Which would deviate the most from ideal behavior?
e.) If a pinhole leak was formed, which has the highest rate of effusion?

at STP, 1mole of any gas has a molar volume of 22.4L
here we have 1L of 2 gases at STP. the number of moles is the same so they have the same number of molecules.

density = mass / volume
this would be SF6

N2

SF6

Rate1/rate2 = √mass2/mass1
√146g/mole / 28g/mole = 2.28
so, N2 is 2.28x faster than SF6

Avogadro's number will tell you the answer to a. Common sense will give you the rest of the answers.