Respuesta :
The following are the steps  to complete and balnce the equation for the given reaction
Explanation:
We are given, NO2– is oxidized to NO3– and Ag is reduced to Ag
NO2– + Ag+ -----> NO3– + Ag(s)
Step 1) Assign the oxidation state to each element reaction
NO2– + Ag+ -----> NO3– + Ag(s)
N= +3 Â Â Â Â Â Â Â Â Â Â Â Â Â N = +5 Â Â Â Â Â Â Â Â Â Â Â Â
O = -2 Â Â Â Â Â Â Â Â Â Â Â Â Â Â O = -2
Ag = +1 Â Â Â Â Â Â Â Â Â Â Â Â Ag = 0
NO2– -----> NO3– ………oxidation half reaction
Ag+ -----> Ag(s) ……….reduction half reaction
Step 2) Balance the element other than O and H
   NO2– -----> NO3–
   Ag+ -----> Ag(s)
Step 3) Balance the O by adding 1 H2O for 1 O
   NO2– + H2O -----> NO3–
   Ag+ -----> Ag(s)
Step 4) Balance the H by adding H+
  NO2– + H2O -----> NO3– + 2H+
   Ag+ -----> Ag(s)
Step 5) Balance the charge by adding electron
  NO2– + H2O -----> NO3– + 2H+ + 2e-
   Ag+ + 1e------> Ag(s)
Step 6) Balance the electron in both half reaction
  NO2– + H2O -----> NO3– + 2H+ + 2e-
   2 Ag+ + 2e------> 2 Ag(s)
