Question

in an experiment 38.65 mL of 0.265 M KMnO4 solution reacted with 18.78 mL of Fe +2 solution. What was the molarity of the iron (II) ion in solution?

Answer 1

Answer:

2.73 M

Explanation:

The balanced reaction that takes place is:

MnO₄⁻ + 8H⁺ + 5Fe²⁺ → Mn²⁺ + 5Fe⁺³ + 4H₂O

Moles of MnO₄⁻ that reacted = 0.265 M * 38.65 mL = 10.24 mmol MnO₄⁻

Moles of Fe²⁺ that reacted = 10.24 mmol MnO₄⁻ * $\frac{5mmolFe^{+2}}{1mmolMnO_{4}^{-}}$ = 51.21 mmol Fe²⁺

Molarity of Iron (II) = 51.21 mmol Fe²⁺ / 18.78 mL =2.73 M