Question

Ferrous ion in mohr's salt titration against potassium permanganate formula

Answer 1

Answer:

Explanation:

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 + 3H2O + 5[O]

Oxidation half reaction –

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

Overall reaction –

2KMnO4 + 10FeSO4(NH4)2SO4.6H2O+8H2O → K2SO4+ 2MnSO4+ 5Fe2(SO4)3+ 102(NH4)2SO4+ 68H2O

The ionic equation involved in the process is given below.

Oxidation half reaction – [Fe2+ – e– → Fe3+] x 5

Reduction half reaction – MnO4– + 8H+ + 5e– → Mn2+ + 4H2O

Overall ionic equation – MnO4– + 8H+ + 5Fe2+ → Mn2+ + 5Fe3+ + 4H2O