Electrochemical Balancing Using Electron Transfer Worksheet
1.  Balance the following redox equations. 

a) KCl + MnO2 + H2SO4 ---> K2SO4 + MnSO4 + Cl2 + H2

b) KMnO4 + FeSO4 + H2SO4 ---> K2SO4 + MnSO4 + Fe2(SO4)3 + H2

c) Zn + HNO3 ------> Zn(NO3 )2 + NH4NO3 + H2

This last equation has some HNO3 that changes oxidation number and some that does not. It may help to write the formulas for HNO3 twice so that you can deal with the two types separately. 

d)  Zn + HNO3 + HNO3 ------> Zn(NO3 )2 + NH4NO3 + H2
2.      Balance the following redox equations, using oxidation numbers. 

(a) HNO3 + H3AsO ---> H3AsO4 + NO + H2

(b) NaI + HOCl -----> NaIO3 + HCl 

(c) KMnO4 + H2C2O4 + H2SO4 -----> CO2 + K2SO4 + MnSO4 + H2

(d) H2SO4 + Al ---> Al2(SO4)3 + SO2 + H2
3. Balance these equations. For each reaction, indicate (a) the oxidizing agent, (b) the reducing agent, (c) the element being oxidized, (d) the element being reduced. Write all equations as net ionic equations.

a) BrO3- + I- + H+ ----> Br- + I2 + H2

b) SeO42- + Cl- + H+ ----> SeO32- + Cl2 + H2

c) Al(s) + NO3- + OH- + H2O ----> NH3 + AlO2-

d) Zn(s) + NO3- + H+ ----> Zn2+ + NH4+ + H2

e) KMnO4 + KNO2 + H2SO4 ----> MnSO4 + H2O + KNO3 + K2SO4
4. Using the electron-transfer method, balance the following equations:

a) Cu + HNO3 ----> Cu(NO3)2 + NO + H2

b) HI + H2SO4 ----> H2O + H2S + I2

c) K2Cr2O7 + FeSO4 + H2SO4 ----> Cr2(SO4)3 + K2SO4 + Fe2(SO4)3 + H2