Question

In a redox titration acidified KMnO4 is reacted with freshly prepared FeSO4 solution. If 20mL of 0.02M KMnO4 was used to react
20mL of FeSO4 solution, Concentration (Molarity) of FeSO4 solution is​

Answer 1

Given info : In a redox titration acidified KMnO4 is reacted with freshly prepared FeSO4 solution.

To find : if 20 ml of 0.02M KMnO4 was used to react 20mL of FeSO4 solution, Concentration (Molarity) of FeSO4 solution is...

solution : no of moles of KMnO4 = volume × molarity

= 20ml × 0.02 M

= 20/1000 L × 0.02 M

= 4 × 10¯⁴ mol

reaction of KMnO4 with FeSO4 in acidic solution is

2KMnO4 + 10FeSO4 + 8H2SO4 => K2SO4 + 2MnSO4 + 5Fe2(SO4)3 + 8H2O

here we see 2 moles of KMnO4 reacts with 10 moles of FeSO4.

∴ 4 × 10¯⁴ mol KMnO4 reacts with 10/2 × 4 × 10¯⁴ = 2 × 10¯³ mol of FeSO4.

now molarity of FeSO4 = no of moles of FeSO4/volume in L

= (2 × 10¯³)/(20/1000)

= 0.1 M

Therefore the molarity of FeSO4 will be 0.1 M