Electrochemistry
Assign oxidation numbers for each of the atoms in the following compounds:
Species	Oxidation Number	Species	Oxidation Number	
HClO	H: +1         O: -2          Cl: +1	KClO3	K: +1          Cl: -5     O:-2	
MnO2	O: -2          Mn: +4	PbO2	Pb: +4     O: -2	
PbSO4	Pb: +2        S: +6          O: -2	K2SO4	K: +1       S: +6       O:-2	
NH4+	N: -3          H: +1	Na2O2	Na: +1    O: -1	
FeO	Fe: +2        O: -2	Fe2O3	Fe: +3     O: -2	
NaIO4	Na: +1     I: +5      O:-2	Fe3O4	Fe: +8/3    O:-2	
Cr2O72-	Cr: +6      O:-2	MnO42-	Mn: +6    O: -2	
NO3-	N: +5     O: -2	ClO3-	Cl: +5       O: -2	

Assign oxidation numbers for all atoms in the following table, determine which element has a change in its oxidation number, and state whether it is oxidation or reduction.
Reactant	Product	Change in Oxidation Number	Oxidation	Reduction 	
MnO4-	MnO42-	Mn 
+7 to +6		√	
K	K+	K
0 to +1	√		
N2	NH3	N
0 to -3		√	
NH3	N2O	N
-3 to +1	√		
P4O10	P4O6	P
+5 to +3		√	
SO42-	SO32-	S
+6 to +4		√	
HClO4	HCl	Cl
+5 to -1		√	
O2	O2-	O
0 to -2		√	
Cr2O72-	Cr3+	Cr
+6 to +3		√