In: Chemistry
For a particular redox reaction NO is oxidized to NO3
The oxidation reaction is : NO 
NO3-
Balancing Nitrogen atoms : NO 
NO3-
Balancing Oxygen atoms : NO+ 2H2O 
NO3-
Balancing Hydrogen atoms : NO+
2H2O+4OH-
NO3- + 4H2O
                                        
NO+ 4OH-
NO3- + 2H2O
Balancing charge : NO+ 4OH-
NO3- + 2H2O
+3e-     ----------(1)
The reduction reaction is Fe
3+
 Fe
2+
Balancing charge : Fe 3+ + 1 e-
 Fe
2+         
----------(2)
The combined equation is obtained by balancing the electrons in both the equations are same.
Eqn (1) + [3xEqn(2) ] gives
NO+ 4OH- + 3Fe 3+ + 3
e-   
NO3- + 2H2O +3e- + 3Fe
2+  
NO+ 4OH- + 3Fe
3+    
NO3- + 2H2O + 3Fe
2+  
This is the balanced equation