number of moles:
1.0 mole CH4 -------------- 22.4 L
moles ------------- 30 L
moles CH4 = 30 * 1 / 22.4 = 1.339 moles
Therefore:
1.0 mole CH4 --------------- 6.02x10²³ molecules
1.339 moles ---------------- molecules CH4
molecules CH4 = ( 1.339 ) * ( 6.02x10²³ ) / 1.0
=> 8.6x10²³ molecules CH4
