A balloon is filled with 3.8 L of helium gas at STP. Approximately how many moles of helium are contained in the balloon?

1 Answer
Apr 16, 2016

Answer:

Approx. #0.17# #mol#

Explanation:

The molar volume of an ideal gas at #"STP"# is #22.4# #L#. We have a volume of #3.8*L# helium gas under these conditions.

Assuming, quite reasonably, that helium behaves ideally, the molar quantity of helium gas is simply the quotient, #(3.8*L)/(22.4*L*mol^-1)# #=# #??# #"moles"# ?