1. Play DHMO warning

2. Writing Formulas and Naming Compounds

3. WHAT DO ALL THESE THINGS HAVE IN COMMON?

4. Oxidation and Reduction+1 -1
2Na0 + Cl202NaCl O I L
Oxidation is loss of electrons or…
xidation s
osing
Na01e- + Na+1
(Half reaction)
Na is oxidized.

5. R I G 2Na0 + Cl202NaCl Cl0 + 1e-Cl-1 eduction s aining
Oxidation and Reduction +1 -1
2Na0 + Cl202NaCl R I G
Reduction is gain of electrons or…
eduction s
aining
Cl0 + 1e-Cl-1
(Half reaction)
Cl is reduced.

6. LEO says GER

7. 2Na0 + Cl202Na+1Cl-1 Secret Agent Man Cl Na Oxidizing agent (O.A.)
Here’s a little trick
Secret Agent Man
OIL
RIG
Oxidizing agent (O.A.)
causes a particle to lose e- (by gaining e- itself)
Reducing agent (R.A.) causes another particle to gain e- (by losing e- itself) Cl Na
Particle
Oxidized
Particle
Reduced
R.A.
O.A.
2Na0 + Cl202Na+1Cl-1

8. 2Na0 + Cl202Na+1Cl-1
The particle oxidized and the particle reduced are
ALWAYS on the same side of the equation!
AND the oxidizing agent and reducing agent
are ALWAYS on the same side of the equation
OIL
RIG

9. So happy togetherrrrrr!
Oxidation and reduction always occur together

10. Ca + S Ca S Practice +2 -2 Ca S S Ca OIL RIG R.A. O.A.+2 -2
OIL
RIG
Ca + S Ca S
R.A.
O.A.
1. Assign charges.
2. Particle oxidized ____ 3. Particle reduced ____
4. Oxidizing agent _____ 5. Reducing agent ____
Then identify: Ca
OIL S
RIG S
O.A. Ca
R.A.

11. Mg + Cl2 Mg Cl2 Practice -1 +2 Mg Cl Cl Mg OIL RIG R.A. O.A.
RIG +2
Mg + Cl2 Mg Cl2
R.A.
O.A.
1. Assign charges.
2. Particle oxidized ____ 3. Particle reduced ____
4. Oxidizing agent _____ 5. Reducing agent ____
Then identify: Mg
OIL Cl
RIG Cl
O.A. Mg
R.A.

12. Mg Cl2 -1 +2 Oxidation States Oxidation states
Oxidation states indicates how many e- are gained, lost, or shared.
Oxidation states
Mg Cl2 +2 -1

13. Rules for Naming Oxidation States
1. In their compounds, the metals of Group 1A always have an oxidation number of +1, the charge on their ions
2. The oxidation number of fluorine (F) is -1 when it is in a compound. +1 -1
NaBr
GIVE RULES SHEET AND RULES W.S.
HAVE THEM WORK ON RULES W.S. IN CLASS USING RULES AS REFERENCE
GO OVER W.S. QUICKLY
GO THROUGH RULES; STAR #1, #2, #5, #7 BECAUSE THEY ARE AN ALWAYS.
GIVE “OXIDATION STATES” WORKSHEET FOR HOMEWORK…START IN CLASS +1 -1
CuF

14. Rules for Naming Oxidation States
3. The oxidation number of a monatomic ion is equal to its charge.
Fe+3….Oxidation # = +3

15. Rules for Naming Oxidation States
4. The sum of the oxidation numbers of all the atoms in the formula of a compound is equal to zero.
5. In their compounds, the metals of group 2A always have an oxidation number of +2, the charge on their ions. +1 -2
K2Se
+1(2) + -2 = 0
= 0
K will always be +1 because it is in group 1 +2 -2
CaS
= 0

16. Rules for Naming Oxidation States
6. In compounds, the oxidation number of oxygen is almost always -2. (Exception: peroxides such as H2O2 or Na2O2 where oxidation number is -1 +1 -1 +1 -1
Na2O2
H2O2
2(+1) + 2(-1) = 0
= 0
2(+1) + 2(-1) = 0
= 0

17. Rules for Naming Oxidation States
7. The oxidation number of an atom of a free element is zero.
8. Hydrogen has an oxidation number of +1 in all compounds, except the metal hydrides, like LiH or CaH2, where oxidation number is -1.
Na Br20
HF KH +1 -1
Metal hydride

18. Rules for Naming Oxidation States
9. In combinations involving nonmetals, the oxidation number of the less electronegative element is positive and of the more electronegative element is negative. +2 -3 +4 -2
SO2
Fe3P2
+4 + 2(-2) = 0
= 0
3(+2) + 2(-3) = 0
= 0

19. Polyatomic Ions
Some covalently bonded groups of atoms act like single atoms in forming ions.
These charged groups of covalently bonded atoms are called radicals or polyatomic ions.
SULFITE: SO AMMONIUM: NH4+1
SULFATE: SO HYDRONIUM: H3O+1
CHLORITE: ClO HYDROXIDE: OH-1
CHLORATE: ClO CYANIDE: CN-1
CHROMATE: CrO PHOSPHATE: PO4-3

20. Rules for Naming Oxidation States
10. The algebraic sum of the oxidation numbers of the atoms of a polyatomic ion is equal to its charge. -2 ( )
= the whole ion (S & 3 O’s) have a
charge of -2
SO3 -2
SO3 ( ) +4 -2
___ + -6 = -2 +4

21. Practice: assign oxidation states (numbers).+2 -2 +1 -1
NaCl
MgS Al
ZnO H2
CrF2
+2 -2 = 0
+1 -1 = 0 +2 -2
+2 -2 = 0
1-3 on ws +2 -1
+2 + 2(-1) = 0
+2 -2 = 0

22. Practice: Assign oxidation states (charges).+1 -1 +3 -2
Fe2O3
K2O2
NO2
HBr
SrH2
MnBr2
= 0
= 0 +2 -1 +1 -1
*Metal hydride
*peroxide
= 0
Do 7
= 0 +2 -1 +4 -2
= 0
= 0

23. Practice: assign oxidation states (numbers).-2 +1 -2 +3
(OH) -1
(Cr2O4)-2
-2 + ___ = -1 +1
____ + 4 (-2) = -2
___ + -8 = -2 +6
2(___) + -8 = -2 +3 +2 -2
PRACTICE!
(S2O3)-2
___ + 3 (-2) = -2
___ + -6 = -2 +4
2(___) + -6 = -2 +2

24. Practice: assign oxidation states (numbers).+1 +6 -2 ?
H2SO4
1(2) + 1x + 4(-2) = 0
2 + 1x + -8 = 0
1x + -6 = 0
Number 4 on sheet
1x = +6
x = +6
= 0
= 0

25. Practice: assign oxidation states (numbers).+1 +7 -2
1(+1) + 1x + 4(-2) = 0
HClO4
K2Cr2O7
1 + 1x -8 = 0
= 0
1x = +7
x = +7 +1 +6 -2
2(+1) + 2x + 7(-2) = 0
PRACTICE!
= 0
2 + 2x -14 = 0
2x = +12
x = +6

26. Al+3 S-2 Al2+3S3-2 = Al2S3 Rb+1 N-3 = Rb3+1N-3 Rb3N1 Refresher
Write down elements with their oxidation numbers.
*More electronegative is written last.
Al+3 S-2
Al2+3S3-2 =
Al2S3
2(+3) + 3(-2)
+6 -6 = 0
Rb+1 N-3 =
Rb3+1N-3
Rb3N1
3(+1) + 1 (-3)
+3 -3 = 0

27. Polyatomic Ions in Compounds
Potassium + chlorite
Calcium + chromate
Magnesium + hydroxide
K+1 & (ClO2)-1 = KClO2
+1 -1 = 0
Ca+2 & (CrO4)-2 = CaCrO4
+2 -2 = 0
Mg+2 & (OH)-1 = Mg(OH)2
*Leave polyatomic in parenthesis!
+2 + 2(-1) = 0

28. Writing Chemical Formulas
Li and I
K and P
Rb and C
Li and Cr2O7-2
Li+1I-1
LiI
K+1P-3
K3P
Rb+1C-4
Rb4C
PRACTICE
Li+1(Cr2O7)-2
Li2Cr2O7

29. Naming Compounds Is the compound ionic or covalent?
If there is a metal or polyatomic ion present, the compound is ionic.
If not, it will be classified as covalent.

30. Naming Ionic Compounds
1. Binary compounds (2 elements)
A. Name the positive part
B. Follow with the root name of the negative part, ending in –ide (monatomic negative ions end in –ide)
CaCl2:
Mg3N2:
NaF:
Calcium Chloride
Magnesium Nitride
Sodium Fluoride

31. Naming Ionic Compounds
2. If a metallic ion forms more than one ion (can have more than 1 oxidation #), the name of the ion includes its oxidation number in roman numerals in parentheses after the name of the metallic ion +2 -2 +1 -1
FeO:
CuCl:
CuCl2:
Hg2S:
Copper(I)Chloride
Iron(II)Oxide +2 -1 -2 +1
Copper(II)Chloride
Mercury(I)Sulfide

32. Naming Ionic Compounds
3. Compounds containing polyatomic ions
Name the positive part followed by the name of the negative part
LiNO3:
Na2SO3:
K2SO4:
CuNO3:
FeSO4
Lithium Nitrate
Sodium Sulfite
PRACTICE
Potassium Sulfate
Copper (I) Nitrate
Iron (II) Sulfate

33. Naming Covalent Compounds (2 Nonmetals)
1. Binary compounds end in –ide
2. However, names include prefixes to indicate the number of atoms in the compound (subscript):
Di = 2
Tri = 3
Tetra = 4
Penta = 5
Hexa = 6
Hepta = 7
Octa = 8
Nona =9
Deca = 10
*mono is not used for the first element
because the 1 is understood.

34. Let’s try it CO2 SO3 N2O3 N2O Carbon dioxide Sulfur trioxide
Dinitrogen trioxide
Dinitrogen monoxide

35. Naming Covalent Compounds
3. Some covalent compounds are known by their common names
H2O
NH3
H2O2
CH4 CO
Water
Ammonia
Hydrogen peroxide
Methane
PRACTICE
Carbon monoxide

36. Naming Compounds Ionic Covalent 2 Elements ends in -ide Roman Numeral?
(metal & nonmetal)
Covalent
Nonmetals
Nonmetals & H
2 Elements
ends in -ide
more than 2 elements
(*polyatomic ions)
ends in –ate or –ite
2 elements
ends in -ide
Use prefixes: di,
Tri, tetra, penta,
Hexa, hepta, octa,
Nona, deca
Ex: CO2 = carbon dioxide
P4O10 = tetraphosphorus
decoxide
Common
Names
NH3: ammonia
H2O: water
CH4: methane
CO: carbon
monoxide
Roman Numeral? No
Only 1 one
oxidation #
for the metal
Yes
More than 1 possible oxidation #
for the metal
Ex: FeS
Fe could be +2 or +3, S is -2
Fe must be +2: Fe+2S-2 = Iron (II) Sulfide