Answer:
The balanced reaction in the acidic medium is:
[tex]2MnO4^-+3CN^-+2H^+\rightarrow 2MnO_2+H_2O+3CNO^-[/tex]
Explanation:
[tex]CN^- + MnO4^-\rightarrow CNO^- + MnO_2[/tex]
1) [tex]CN^-\rightarrow CNO^-[/tex] ( oxidation)
Balance oxygen by adding water :
[tex]CN^-+H_2O\rightarrow CNO^-[/tex]
Now , balance hydrogen by adding hydrogen ions on the side where hydrogen are less.
[tex]CN^-+H_2O\rightarrow CNO^-+2H^+[/tex]
Add electrons to balance charge where positive charge is more.
[tex]CN^-+H_2O\rightarrow CNO^-+2H^++2e^-[/tex]..[1]
2) [tex]MnO4^-\rightarrow MnO_2[/tex] (reduction)
Balance oxygen by adding water :
[tex]MnO4^-\rightarrow MnO_2+2H_2O[/tex]
Now , balance hydrogen by adding hydrogen ions by adding them on the side where hydrogen are less.
[tex]MnO4^-+4H^+\rightarrow MnO_2+2H_2O[/tex]..[2]
Add electrons to balance charge where positive charge is more.
[tex]MnO4^-+4H^++3e^-\rightarrow MnO_2+2H_2O[/tex]..[2]
3 × [1] + 2 × [2]
The balanced reaction in the acidic medium is:
[tex]2MnO4^-+3CN^-+2H^+\rightarrow 2MnO_2+H_2O+3CNO^-[/tex]
