10. What is the molarity of a MnO4 - solution if 23.5 mL of this solution is required to react completely with 30.0 mL of 0.134 M Fe2 solution according to the equation 5Fe2 (aq) MnO4 - (aq) 8H (aq) - --> 5Fe3 (aq) Mn2 (aq) 4H2O (l)

The molarity of a MnO4 - solution

= 0.0342 M

Explanation:

Equation of reaction:

5Fe2 (aq) MnO4 - (aq) 8H (aq) - --> 5Fe3 (aq) Mn2 (aq) 4H2O (l)

This is an example of redox titration.

Using titration formula:

CAVA/CBVA = NA/NB

where CA is the molarity of Fe2 + = (0.134 M)

CB is the molarity of MnO4 - = (?)

VA is the volume of Fe2 + = (30mL)

VB is the volume of MnO4 - = (23.5mL)

NA is the numeric coefficient of Fe2 + in the equation of reaction = (5)

NB is the numeric coefficient of MnO4 - in the equation of reaction = (1)

Substituting the values into the formula;

0.134*30/CB*23.5 = 5/1

Therefore CB = 0.134*30/23.5*5

= 0.0342 M