Answer:
(4) 266 moles
Explanation:
We have Dinitrogen Pentoxide N2O5
6.41*10^25 molecules are given
No of Moles of N2O5 = [tex]\frac{No of Molecules }{Avogadro's Number}[/tex]
= [tex]\frac{6.41 * 10^25}{6.022*10^23}[/tex]
= 106.5 mol
Now using Unitary Method
2 Mole of Nitrogen pentoxide require 5 mole of Oxygen to form N2O5
1 mole of N = [tex]\frac{5}{2}*O[/tex]
In 106.5 mole of N = [tex]\frac{5}{2}*106.5[/tex] = 266.25 mole
So, 6.41*10^25 molecules of N2O5 will require 266.25 mole of Oxygen atoms.