What volume is occupied by #4.02 * 10^22# molecules of helium gas at STP?

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Answer 1 · 2016-02-11T09:25:14

The molar volume of an ideal gas at STP is #22.4# #dm^3#, or #22.4# #L#.

In one mole of gas there are Avogadro's number of particles. There are #6.022# #xx# #10^23# #"particles mol"^-1#.

So how many moles are there in #4.02xx10^22# helium particles?

It is simply the quotient: #(4.02xx10^22" helium particles")/(6.022xx10^23" helium particles mol"^-1 )#

#=# #?? mol#

The volume of course is the prior quotient mulitplied by the molar volume of an ideal gas:

#(4.02xx10^22" helium particles")/(6.022xx10^23" helium particles mol"^-1 )# #xx# #22.4*L*mol^-1#

#=# #??L#