Answer:
number of moles of He added = 153.2 moles
Explanation:
given data
initial volume = 2,280 L
final volume = 5,710 L
final volume of helium = 255 mol
solution
we get here initial number of moles of He that is
initial number of moles = [tex]\frac{2280}{22.4}[/tex]
initial number of moles = 101.8 moles
and
final number of moles is = [tex]\frac{5710}{224}[/tex]
final number of moles = 255 moles
so that number of moles of He added is
number of moles of He added = 255 - 101.8
number of moles of He added = 153.2 moles