1. Naming and Formula Writing
Nomenclature
Naming and Formula Writing

2. Nomenclature
A term that describes the system of principles, procedures, rules, or terms related to naming.
We use nomenclature to have a uniform set of rules for naming and writing formulas for chemical compounds.
The IUPAC (International Union of Pure and Applied Chemistry) establishes these rules.

3. Review of Key Vocabulary
Ionic Compounds – contain bonds between metals and nonmetals
A bond involving a TRANSFER of electrons
A bond between cations and anions
Cation – An atom that has lost one or more electrons. It has a positive (+) charge.
Anion – An atom that has gained one or more electrons. It has a negative (-) charge.

4. More Key Vocabulary
Binary Compound – A substance that has only 2 different elements.
MgCl2
NaCl
H2O
Ternary Compound – A substance that has 3 or more different elements.
NaOH
H2SO4
CH3Cl

5. More Key Vocabulary
Prefix – A few letters placed at the beginning of a word to change its meaning.
Nonmetal
Carbon dioxide – CO2
Carbon monoxide – CO

6. More Key Vocabulary
Ending / Suffix – A few letters placed at the end of a word to change its meaning.
Laughable
Portable
Calcium Sulfate – CaSO4
Calcium Sulfite – CaSO3
Calcium Sulfide – CaS
Calcium Oxide - CaO

7. Ionic Nomenclature Always write the cation and then the anion.
NaCl – NEVER ClNa
Sodium Chloride – NEVER Chloride Sodium

8. Binary Ionic Nomenclature (Formula  Name)
1-State the name of the cation
2-State the name of the anion
For single elements, drop the ending, substitute the suffix –ide
Cl = Chlorine  Chloride
F = Fluorine  Fluoride
Br = Bromine  Bromide
I = Iodine  Iodide
O = Oxygen  Oxide
S = Sulfur  Sulfide
N = Nitrogen  Nitride
P = Phosphorus  Phosphide
C = Carbon  Carbide

9. Practice Binary Ionic Naming
CaCl2 – Calcium chloride
MgO – Magnesium oxide
AlF3 – Aluminum fluoride
SrBr2 – Strontium bromide
Ba3N2 – Barium nitride

10. More Key Vocabulary
Subscript – A number that is written smaller and to the lower right of an element or group of elements telling you how many of that element or group there are.
H2O Mg(ClO3)2

11. More Key Vocabulary
Superscript – A number that is written smaller and to the upper right of an element or group of elements telling you the charge of the element or group of elements.
H3O+ Ca+2 SO4-2 N+3

12. Binary Ionic Nomenclature (Name  Formula)
A little more difficult
1 - Write the symbol of cation and anion including charge
2 - Use subscripts to balance the charge of the compound
do not need to write a 1 – it is assumed
All ionic compounds have a neutral charge

13. Binary Ionic Nomenclature (Name  Formula)
Calcium Bromide
Ca Br-
There is a +2 charge and a -1 charge
An extra -1 charge is needed Ca+2 Br- Br-
= 0
Need 1 calcium and 2 bromine
CaBr2

14. “Crisscross” Method Check Work
Charge of the cation becomes the subscript for anion
Charge of the anion becomes the subscript for the cation
Aluminum Sulfide
Al+3 S-2  Al2S3
Notice the + or – charge is dropped
Simplify to smallest whole numbers
Mg+2 O-2  Mg2O2  MgO
Check Work

15. Practice Binary Ionic Formula Writing
Calcium Sulfide – CaS
Barium Chloride – BaCl2
Lithium Fluoride – LiF
Aluminum Nitride – AlN
Sodium Phosphide – Na3P

16. More Key Vocabulary
Transition Element – An element in group 3 through 12 on the periodic table.
Oxidation State – A possible charge for an ion of a given element.
Located in top right corner of element square on PT
All “free elements” have oxidation states of ZERO
Many elements only have one oxidation state
Many (BUT NOT ALL) transition elements have more than one oxidation state
Can have different charges!
Some, but only a few, other metals have multiple oxidation states

18. More Key Vocabulary
Roman Numerals – A numeral system established in ancient Rome. The system is based on certain letters which combine to signify a number.
1 = I
2 = II
3 = III
4 = IV
5 = V
6 = VI
7 = VII

19. Binary Ionic Nomenclature Multiple Oxidation States (Formula  Name)
Name the Cation
In Parenthesis, write the oxidation number of the cation using Roman Numerals
Name the Anion
Examples: Iron (II) oxide, Iron (III) oxide

20. Determining Oxidation Number Based on Formula
We will use the “Multiply Down, Add Across” Method
First, rewrite the formula
Second, below each element, write the number of each element
Third, write any known charges, or write an “x” for an unknown charge
We typically know the charges for nonmetals
Group 15 = -3
Group 16 = -2
Group 17 = -1
Fourth, multiply down, and then create an algebraic expression so you may add across.

21. Multiply Down, Add Across
Fe2O3 FeO
Charge of the Compound
(Always 0, unless it is an ion)
# of each element 2 3 1 1
Known Charges X -2 X -2
2X + -6 = 0
X + -2 = 0
Solve
2X = +6
X = +2
X = +3
The oxidation state of Fe is +3
The oxidation state of Fe is +2
Iron (III) oxide
Iron (II) oxide

22. Practice Binary Ionic Naming Using Elements w/
Practice Binary Ionic Naming Using Elements w/. Multiple Oxidation States
MnBr4 – Manganese (IV) bromide
CoCl3 – Cobalt (III) chloride
Cr2O3 – Chromium (III) oxide
Ni3N2 – Nickel (II) nitride
TiS2 – Titanium (IV) Sulfide
Check to make sure the oxidation state you think is correct is a possible oxidation state according to your periodic table

23. Practice Binary Ionic Formula Writing Using Elements w/
Practice Binary Ionic Formula Writing Using Elements w/. Multiple Oxidation States
Easier than naming
Use the “crisscross” method
Remember to reduce subscripts…
Manganese (VII) sulfide – Mn2S7
Chromium (VI) phosphide – CrP2
Copper (II) chloride – CuCl2
Platinum (IV) Oxide – PtO2

24. Final Key Vocabulary
Polyatomic Ion – A particle that contains more than one atom and has a positive or negative charge.
Table E
First 3 are cations, the rest are all anions

25. Ternary Ionic Nomenclature (Formula  Name)
Same Rules
Write Cation first, then Anion
Polyatomic Ions have their own endings
NaClO2 = Sodium chlorite

26. Practice Ternary Ionic Naming
AgNO3 – Silver nitrate
CaSO4 – Calcium sulfate
Na2S2O3 – Sodium thiosulfate
Zn3(PO4)2 – Zinc phosphate
KMnO4 – Potassium permanganate
Hg2O – Dimercury (I) oxide
NH4Cl – Ammonium chloride
NH4OH – Ammonium hydroxide

27. Ternary Ionic Nomenclature (Name  Formula)
Trickiest of them all…
1 - Write the symbol of cation and anion including charge
This may mean a whole polyatomic ion
2 - Use subscripts to balance the charge of the compound
do not need to write a 1 – it is assumed
3 - Any subscripts for a polyatomic ion need to be written outside parenthesis that surround the polyatomic ion.
May still use “crisscross” method

28. Ternary Ionic Nomenclature (Name  Formula)
Aluminum Sulfate
Al+3 SO4-2
There is a +3 charge and a -2 charge
We need 2 +3 charges and 3 +2 charges
Al+3 Al+3 SO4-2 SO4-2 SO4-2
= 0
Need 2 aluminums and 3 sulfates
Al2(SO4)2

29. “Crisscross” Method w/. Polyatomic Ions
Charge of the cation becomes the subscript for anion
Charge of the anion becomes the subscript for the cation
Iron (II) hydroxide
Fe+2 OH- 
YOU NEED PARENTHESIS
There are not 2 H’s, there are 2 OH’s
Simplify to smallest whole numbers
Ca+2 S2O3-2  Ca2(S2O3)2 
Check Work
Fe(OH)2
CaS2O3

30. Practice Ternary Ionic Formula Writing
Calcium Sulfite – CaSO3
Ammonium sulfide – (NH4)2S
Cobalt (III) phosphate – CoPO4
Copper (II) nitrate – Cu(NO3)2
Ammonium dichromate – (NH4)2Cr2O7

31. Ionic Nomenclature Mega Practice
Ca3(PO4)2
Calcium phosphate
NaOH
Sodium hydroxide
FeCl3
Iron (III) chloride
CuSO3
Copper (II) sulfite
KCN
Potassium cyanide
KBr
Potassium bromide
Sodium sulfide
Na2S
Barium nitride
Ba3N2
Copper (II) peroxide
CuO2
Manganese (VII) oxide
Mn2O7
Strontium perchlorate
Sr(ClO4)2
Chromium (III) nitrite
Cr(NO2)3

32. More Key Vocabulary
Covalent Compounds – contain bonds between one or two nonmetallic elements
Remember when Ionic Bonding was so short and easy, and Covalent Bonding was so long and tough?
OPPOSITE HERE
Naming Covalent Compounds is EASY

33. Covalent Prefixes # atoms Prefix 1 -mono 6 -hexa 2 -di 7 -hepta 3 -tri
Only hard part:
You need to MEMORIZE these prefixes
# atoms
Prefix 1
-mono 6
-hexa 2
-di 7
-hepta 3
-tri 8
-octa 4
-tetra 9
-nona 5
-penta 10
-deca

34. Covalent Nomenclature (Formula  Name)
Name the elements in the order they are listed
Use the prefixes to show how many of each element
DON’T use “mono” for the first element
Avoid difficulty saying words by eliminating “ao” or “oo” by just using “o”
Hexaoxide is too difficult to say, just write Hexoxide
Change the ending of the second element to -ide

35. Covalent Nomenclature Practice (Formula  Name)
N2O – Dinitrogen monoxide
NO2 – Nitrogen dioxide
CO – Carbon monoxide
CO2 – Carbon dioxide
CCl4 – Carbon tetrachloride
NI3 – Nitrogen triiodide
***NH3 – Ammonia
***H2O – Water
CS2 – Carbon disulfide
N2O5 – Dinitrogen pentoxide
*** There are common names for these we use instead, H2O you should know, NH3 is in your reference table…

36. Covalent Nomenclature (Name  Formula)
Even Easier!
Use the prefixes to guide you for what the subscripts need to be
Dihydrogen monosulfide
Di = 2  H2
Mono = 1  S
H2S

37. Covalent Nomenclature Practice (Name  Formula)
Carbon tetrabromide – CBr4
Iodine dioxide – IO2
Phosphorus pentachloride – PCl5
Dichlorine heptoxide – Cl2O7
Diphosphorus trioxide – P2O3

38. Ionic + Covalent Nomenclature
The trick to naming and formula writing is determine first if the example is an ionic or covalent compound.
Covalent
P4O10
Dinitrogen monoxide
TiCl3
Ammonium thiosulfate
Calcium Phosphate
Ammonia
Covalent
Tetraphosphorus decoxide
N2O
Ionic
Ionic
Titanium (III) chloride
(NH4)2S2O3
Ionic
Covalent
Ca3(PO4)2
NH3