Question

Rusting is a chemical reaction between Iron metal [Fe(s)] and oxygen gas [O2(g)] in a slightly acidic environment. Rusting is actually a multi-step reaction, however it has the net overall reaction of:

4Fe+3O2--->2FeO3

If 100.0 g of iron metal are converted into rust, how many moles of rust will have formed? (Assume unlimited oxygen gas.)
*Hint* You already converted 100.0 g of Fe into moles of Fe in a previous question, start there.

Answer 1

0.895 mole of Fe₂O₃.

Step-by-step explanation:

We'll begin by calculating the number of mole in 100 g of Fe. This can be obtained as follow:

Molar mass of Fe = 56 g/mol

Mass of Fe = 100 g

Number of mole of Fe =?

Mole = mass / molar mass

Number of mole of Fe = 100 / 56

Number of mole of Fe = 1.79 mole

Finally, we shall determine the number of mole of Fe₂O₃ produced by the reaction of 100 g (i.e 1.79 moles) of Fe. This can be obtained as follow:

4Fe + 3O₂ — > 2Fe₂O₃

From the balanced equation above,

4 moles of Fe reacted to produce 2 moles of Fe₂O₃.

Therefore, 1.79 moles of Fe will react to produce = (1.79 × 2)/4 = 0.895 mole of Fe₂O₃.

Thus, 0.895 mole of Fe₂O₃ was obtained from the reaction.