Manganate (VII) And Iodine Titration

Question 1

How do you carry out a manganate (VII) titration

Answer 1

Standard solution of potassium manganate to Burette
Put solution analysing with excess sulphuric acid to provide H+
End point is first permanent pink
Repeat until you get concordant results

Question 2

What is the oxidation of MnO4-

Answer 2

MnO4- +8H+ +5e- -> Mn2+ +4H20

Question 3

Iodine / thio sulphate oxidation and reduction

Answer 3

2S2O3 -> S4O62- +2e

I2 +2e -> 2I-

Question 4

Procedure for iodine/ thio sulphate reactions

Answer 4

Add standard solution Na2S2O3 to Burette
Add KI to solution in conical flask and wait until iodine forms
Titrate and add starch