KI+Cl2→KCl+I2
Ionic equation, I−+Cl2→Cl−+I2
1st step: Splitting into two half reactions,
I−→I2(Oxidation); Cl2→Cl−(Reduction)
2nd step: Making number of atoms equal,
2I−→I2; Cl2→2Cl−
3rd step: Adding electrons to the sides deficient in electrons,
2I−→I2+2e;Cl2+2e→2Cl−
4th step: Adding both the half reactions,
2I−+Cl2→I2+2Cl−
Converting it into molecular form,
2K++2I−+Cl2→I2+2Cl−+2K+
or
2KI+Cl2→I2+2KCl.