What volume is occupied by 4.021022 molecules of helium gas at STP?

1 Answer
Feb 11, 2016

The molar volume of an ideal gas at STP is 22.4 dm3, or 22.4 L.

Explanation:

In one mole of gas there are Avogadro's number of particles. There are 6.022 × 1023 particles mol1.

So how many moles are there in 4.02×1022 helium particles?

It is simply the quotient: 4.02×1022 helium particles6.022×1023 helium particles mol1

= ??mol

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

4.02×1022 helium particles6.022×1023 helium particles mol1 × 22.4Lmol1

= ??L