Respuesta :

Answer:

0.87mole

Explanation:

The reaction equation is given as;

    4Fe + 3O₂  →  2Fe₂O₃

Number of moles of Fe₂O₃ in 138.5g

To solve this problem;

 Number of moles = [tex]\frac{mass}{molar mass}[/tex]

Molar mass of Fe₂O₃ = 2(56) + 3(16) = 160g/mol

 Now;

          Number of moles  = [tex]\frac{138.5}{160}[/tex]   = 0.87mole