1. RULES OF OXIDATION NUMBER ASSIGNMENT
STEPS IN ASSIGNNING OXIDATION NUMBERS
1) IF THE PERIODIC TABLE GIVES ONLY ONE OXIDATION STATE, USE THAT THAT STATE. EXAMPLE Zn+2 .
2) APPLY THE RULES OF THIS POWERPOINT TO SOLVE FOR OXIDATION NUMBERS OF ELEMENTS WITH MULTIPLE OXIDATION STATES.
3) IF A MULTIPLE OXIDATION STATE ELEMENT HAS NO RULE, ASSIGN IT A VARIABLE AND SOLVE USIMNG THE ALGEBRA RULE(SLIDE 3).

2. THE SUM OF THE OXIDATION NUMBER (STATE ) OF EACH ATOM IN A COMPOUND EQUALS THE CHARGE OF THAT COMPOUND. KMnO GIVEN: K IS +1(GROUP 1 RULE ), O IS -2 (OXYGEN RULE) Mn HAS MULTIPLE STATES(PERIODIC TABLE) +1 + X + 4(-2) = 0
ALGEBRA RULE EXAMPLES.
Use group one to find other elements.
note: caution with oxygen in binary compounds
Li2O2
2(+1) + 2(X) = 0
X=O (oxygen) = -1
Use group one as a known for
muli oxidation stare elements
Na2SO4
2(+1) + (X) + 4(-2)= 0
X = S = +4 each S

3. GROUP ONE RULE EXAMPLES.
GROUP ONE ELEMENTS ARE ALWAYS 1+ IN COMPOUNDS OR AS FREE (AQ) IONS. Ex in NaCl EACH Na has an oxidation state of in K2SO4 EACH K has an oxidation state of A Li+1 (aq) free ion has an oxidation number of 1+.
GROUP ONE RULE EXAMPLES.
Use group one as a known for
muli oxidation stare elements.
Na2SO4
2(+1) + (X) + 4(-2)= 0
X = S = +4 each S
Use group one to find other elements.
Li2O2
2(+1) + 2(X) = 0
X=O (oxygen) = -1 each

4. GROUP ONE RULE EXAMPLES.
GROUP TWO ELEMENTS HAVE AN OXIDATION STATE OF 2+ IN COMPOUNDS AND AS FREE (AQ) IONS.   Ex in1) BaCl2 EACH Ba has an oxidation state of JJIBGO 2) In Ca3(PO4)2 EACH Ca has an oxidation state of A free Mg+2 ION (AQ) has an oxidation state of 2+.  
GROUP ONE RULE EXAMPLES.
Use group TWO as a known for
muli oxidation stare elements.
Ca3(PO4)2
3(+2) + 2(x) + 8(-2)=0
X = P = +6 each P
Use group TWO to find other elements.
BaO2
1(+2) + 2(X) = 0
X=O (oxygen) = -1 each

5. ALL UNCOMBINED NEUTRAL (ELEMENTAL STATE) ATOMS HAVE AN OXIDATION STATE OF 0. THE NONPOLAR COVALENT DIATOMOIC MOLECULES OF THE PERIODIC TABLE ALSO HAVE AN OX# OF 0. EX: Au0, Fe0, Na0, etc. EX: H2, O2, N2, Cl2, Br2, I2, F2 are3 all in the 0 oxidation state

6. THE OXIDATION NUMBER OF IONS IS THE IONIC CHARGE
THE OXIDATION NUMBER OF IONS IS THE IONIC CHARGE. EX: Au+2 = 2+, Fe+3 = 3+, Na+ = 1+, etc. EX: NO3 - HAS AN OXIDATION NUMBER OF 1- FOR THE (EACH) POLY ATOMIC ION GROUP.

7. Fluorine is always 1- in its compounds
THE OXYGEN RULES: Each oxygen USUALLY has an oxidation state of 2- in compounds, 0 in O2.
EX, in H2O oxygen is 2-
In H2SO4 EACH oxygen is 2-
IMP -- EXCEPTION #1– when oxygen is contained in a PEROXIDE, it has an oxidation state of 1-. PEROXIDES - contain the peroxide ion (O2-2), EACH oxygen is peroxides are when 2 group one elements combine with the peroxide ion H2O2, Li2O2, K2O2 are peroxides, each O is 1- BaO2, CaO2, MgO2 are peroxides, each O is 1- IMP -- EXCEPTION #2 – when oxygen is combined with FLOURINE, its oxidation state is 1+ or 2+. Fluorine is electronegative enough to oxidize oxygen. EXAMPLE : in FO the oxygen is +1, in F2O each oxygen is 2+
USE CAUTION IN BINARY COMPOUNDS OF OXYGEN AND HYDROGEN -- CHECK FOR RULE EXCEPTIONS.
Fluorine is always 1- in its compounds

8. THE HYDROGEN RULE: THE OXIDATION STATE OF HYDROGEN IS USUALLY 1+   EX in H2O each hydrogen is 1+   IMP-EXCEPTION – in GROUP 1 METAL HYDRIDES the hydrogen is 1-, hydrogen is electronegative enough to oxidize group one metals. EX: NaH, KH etc the hydrogen is 1-  
USE CAUTION IN BINARY COMPOUNDS OF OXYGEN AND HYDROGEN -- CHECK FOR RULE EXCEPTIONS.