Question

Determine the molarity of the given KMnO4 solution with the help of supplied my20 Mall side the solution by traction method

Answer 1

Answer:

The titration of potassium permanganate

(KMnO4) against Mohr salt is an example

of redox titration. In close proximity to

the endpoint, the action of the indicator is analogous to the other types of visual colour titrations in oxidation-reduction

(redox) titrations.

Aim: To determine the strength of a given

potassium permanganate solution against

standard ferrous ammonium sulfate (Mohr's

salt) solution.

Theory:

Potassium permanganate is a strong oxidant in the presence of sulfuric acid.

Mohr salt is a double salt forming a single

crystalline structure having the formula

(NH4</sub2SO4. FeSO4. 6H2O. The

chemical name for Mohr's salt is ferrous

ammonium sulfate.

In this titration Mohr salt acts as a reducing agent and potassium permanganate acts as an oxidising agent. So, the reaction. between Mohr's salt and potassium permanganate is a redox reaction. In this redox reaction, ferrous ion from Mohr's salt gets oxidised and pink coloured of manganese present in potassium

permanganate, which is in the +7 oxidation. state gets reduced to colourless Mn2+

state.

The chemical reaction and the molecular

chemical equation is given below.

Reduction half reaction -

2KMnO4 + 3H2SO4 → K2SO4 + 2MnSO4 + 3H20 +5[0]

Oxidation half reaction -

2FeSO4(NH4)2SO4.6H2O + H2SO4 + 5[0] → Fe2(SO4)3 + 2(NH4)2SO4 + 13H2O x 5

Overall reaction -

2KMnO4 +

10FeSO4(NH4)2SO4.6H2O+8H20 → K2SO4+ 2MnSO4+ 5Fe2(SO4)3+

10(NH4)2SO4+68H20

The ionic equation involved in the process

is given below.

Oxidation half reaction [Fe2+ Fe3+ -

e-] x 5

Reduction half reaction - MnO4- + 8H+ +

5e Mn2+ + 4H2O Overall ionic equation - MnO4- + 8H+ +

5Fe2+ → Mn2+ + 5Fe3+ + 4H2O

This titration is based upon

oxidation-reduction titrations. When ferrous

ammonium sulfate solution is titrated

against potassium permanganate in the

presence of acidic medium by sulfuric

acid. Acidic medium is necessary in order

to prevent precipitation of manganese

oxide. Here KMnO4 acts as a self indicator

and this titration is called permanganate

titration.

Materials Required:

Mohr's salt (ferrous ammonium sulfate) Potassium permanganate solution

Dilute sulfuric acid

Chemical balance

Burette

Burette stand

Pipette Conical flask

Funnel

Measuring flask Weighing bottle

White tile Burnet

Wire gauze