Answer:
Molecules of oxygen [tex]= 6.86 * 10^{23}[/tex]
Explanation:
The balanced equation of reaction between iron and oxygen is
4 Fe + 3 O2 → 2 Fe2O3
4 moles of iron react with 3 moles of oxygen.
Mass of one mole of iron is 55.845
number of iron moles in 84.9 grams of solid iron is equal to
[tex]\frac{84.9}{55.845} \\= 1.52[/tex]
Now 1 mole of iron will react with [tex]\frac{3}{4} = 0.75[/tex] mole of oxygen
Thus 1.52 moles of iron will react with [tex]0.75 * 1.52 = 1.14[/tex] moles of oxygen
Number of atoms of oxygen in 1.14 moles
[tex]1.14* 6.02 * 10^{23}\\[/tex]
[tex]= 6.86 * 10^{23}[/tex]
