Equalize The Redox Reaction

Redox is chemical reaction which contain reduction and oxidation. Redox happened in acid or alkaline environment. Steps to equal redox is easy. Now, I will share the steps to equal redox reaction. Let’s check it out guys!

Redox equalization in acid enviroment with half reaction

Find the speci that involved in reduction and oxidation 

Make same the atom in that speci 

Same the sum of O with add H₂O 

Balance the sum of H by add H⁺ 

Make the charge same between two sides by add electron 

Unite reduction and oxidation together 

This is The Example 

MnO₂ + HCl → MnCl₂ + Cl₂ (acid)

Reduction	Oxidation
MnO2 → MnCl2	HCl → Cl2
MnO2 → MnCl2 + 2H2O	2HCl → Cl2
MnO2 + 4H+ → MnCl2 + 2H2O	2HCl → Cl2 + 2H+
MnO2 + 4H+ + 4e → MnCl2 + 2H2	2HCl → Cl2 + 2H+ + 2e

Then we unite the reduction and oxidation 

MnO₂ + 4H⁺ + 4e → MnCl₂ + 2H₂O ( x1 )

2HCl → Cl₂ + 2H⁺ + 2e ( x2 )

And we get the final result is 

MnO₂ + 4HCl → MnCl₂ + 2H₂O + 2Cl₂

Redox equalization in alkaline environment with half reaction 

Find the speci that involved in reduction and oxidation 

Make same the atom in that speci 

Same the sum of O with add H₂O 

Balance the sum of H by add H⁺ 

Plus OH^- in both side 

Make the charge same between two sides by add electron 

Unite reduction and oxidation together 

Use this example 

Al + NO₂^- → AlO₂ + NH₃ (alkaline)

Reduction	Oxidation
NO2- → NH3	Al → AlO2
NO2- → NH3 + 2H2O	Al + 2H2O → AlO2
NO2- + 7H+ → NH3 + 2H2O	Al + 2H2O → AlO2 + 4H+
NO2- + 7H+ + 7OH- → NH3 + 2H2O + 7OH-	Al + 2H2O + 4OH- → AlO2 + 4H+ + 4OH-
NO2- + 7H2O → NH3 + 2H2O + 7OH-	Al + 2H2O + 4OH- → AlO2 + 4H2O
NO2- + 5H2O → NH3 + 7OH-	Al + 4OH- → AlO2 + 2H2O
NO2- + 5H2O + 6e → NH3 + 7OH-	Al + 4OH- → AlO2 + 2H2O + 4e

unite the reduction and oxidation 

NO₂^- + 5H₂O + 6e → NH₃ + 7OH^‑ ( x2 )

Al + 4OH^- → AlO₂ + 2H₂O + 4e ( x3 )

We will get 

2NO₂^- + 10H₂O + 3Al + 12OH^- → 2NH₃ + 14OH^- + 3AlO₂ + 6H₂O

And the final result is 

2NO₂^- + 4H₂O + 3Al → 2NH₃ + 2OH^- + 3AlO₂

Good Luck Guys !