Answer:
3.35 mole.
Explanation:
- It is a stichiometriy oriented problem.
- From the balanced equation: Fe + 2NiO(OH) + 2H₂O → Fe(OH)₂ + 2Ni(OH)₂
- It is clear that 1.0 mole of Fe reacts with 2.0 moles of NiO(OH) to produce 1.0 mole of Fe(OH)₂.
- Fe reacts with NiO(OH) with 1:2 ratio.
- So, 6.70 mole of NiO(OH) will react completely with (6.70 x 0.5 = 3.35 mole) of Fe. But Fe is present in excess (4.20 mole), so the limiting reactant is NiO(OH).
Using cross multiplication and from the stichiometry:
2.0 moles of NiO(OH) produce → 1.0 mole of Fe(OH)₂
6.70 mole of NiO(OH) produce → ??? mole of Fe(OH)₂
∴ The number of moles of Fe(OH)₂ produced = (1.0 mole) *6.70 mole) / (2.0 mole) = 3.35 mole.