Question

BALANCE THE FOLLOWING EQUATION IN ACIDIC SOLUTION. 1. Mn2+ + IO3- MnO2 + I2

Answer 1

Mn in Mn+2 has oxidation state of +2
Mn in MnO2 has oxidation state of +4
So, Mn in Mn+2 is oxidised to MnO2

I in IO3- has oxidation state of +5
I in I2 has oxidation state of 0
So, I in IO3- is reduced to I2





Reduction half cell:
2 IO3- + 10e- --> I2
Oxidation half cell:
Mn+2 --> MnO2 + 2e-
Balance number of electrons to be same in both half reactions

Reduction half cell:
2 IO3- + 10e- --> I2
Oxidation half cell:
5 Mn+2 --> 5 MnO2 + 10e-

Lets combine both the reactions.
2 IO3- + 5 Mn+2 --> I2 + 5 MnO2
Balance Oxygen by adding water

2 IO3- + 5 Mn+2 + 4 H2O --> I2 + 5 MnO2

Balance Hydrogen by adding H+
2 IO3- + 5 Mn+2 + 4 H2O --> I2 + 5 MnO2 + 8 H+
This is balanced chemical equation in acidic medium

Answer:

2 IO₃^- + 5 Mn²⁺ + 4 H₂O --> I₂ + 5 MnO₂ + 8 H⁺