1. Names & Formulas
(Nomenclature)

2. Anatomy of a Chemical Formula
Al2SO4
Numbers at the bottom are called subscripts.
They tell how many atoms of one type are in a compound.
Ca+2
Numbers at the top are called superscripts.
They tell you the charge of the atom.

3. Polyatomic Ions CO3-2 carbon = 1 oxygen = 3 overall charge = -2
Group of atoms that have an overall charge. You will find both subscripts and superscripts in polyatomic ions.
CO3-2 carbon = 1
oxygen = 3
overall charge = -2

4. 3 Categories of Compounds
Ionic
Acids & Bases
Molecular

5. 1) Ionic Compounds Contain IONIC bonds.
Formed between metals and non-metals.
Ions combine in small, whole number ratios.
The sum of oxidation numbers will be zero! (they are neutral)

6. Binary Ionic Compounds
All contain two elements.
All end in “ide”.

7. Binary Ionic Compounds
To write formula:
1) Write + and - ions.
2) Reduce oxidation numbers, if possible.
3) “Criss-Cross” number only to become subscript for other ion.

8. NaCl Mg3N2 CaO sodium chloride magnesium nitride calcium oxide
Examples…
NaCl
sodium chloride
magnesium nitride
calcium oxide
Mg3N2
CaO

9. Binary Ionic Compounds
To Name:
1) Cations (+) retain the name of the element.
Anions (-) keep the root name but add “ide” ending.

10. LiF SrCl2 Al2O3 Examples… Lithium fluoride Strontium chloride
Aluminum oxide

11. Multi-Charge Metals
Most of the transition metals (and lead and tin) have variable oxidation numbers.
(they can have more than one)

12. Roman numerals are used to indicate charges for these elements.
Roman numerals always belong to the metal.
(are always positive)

13. IMPORTANT EXCEPTIONS!
Silver always forms a 1+ ion.
Zinc always forms a 2+ ion.
Cadmium always forms a
2+ ion.

14. FeO Fe2O3 CrS2 Iron (II) oxide iron(III) oxide chromium (IV) sulfide
Examples…
FeO
Iron (II) oxide
iron(III) oxide
chromium (IV) sulfide
Fe2O3
CrS2

15. CuO Cr2Se3 PbS2 Examples… Copper (II) oxide chromium (III) selenide
Lead (IV) sulfide

16. Ternary Ionic Compounds
Contain 3 or more elements. (not binary)
Contain at least one
Polyatomic Ion.
(look on the back of your P.T.)

17. Polyatomic Ions All P.A.I. contain at least two different elements.
Example:
Chlorate  ClO3-1
(Contains chlorine and oxygen)

18. To name/write formulas:
Use the same rules as binary ionic compounds.
Enclose P.A.I. in parenthesis when necessary.

19. Aluminum phosphate AlPO4 Sodium sulfate Na2SO4 Iron (II) bromate
Examples…..
Aluminum phosphate
AlPO4
Sodium sulfate
Na2SO4
Iron (II) bromate
Fe(BrO3)2

20. Examples… CaCO3 Cu(NO3)2 (NH4)3N Calcium carbonate Copper (II) nitrate
Ammonium nitride

21. Naming
Acids & Bases

22. All traditional acids begin with Hydrogen (H).
2) Acids and Bases:
All traditional acids begin with Hydrogen (H).
All traditional bases end with Hydroxide (OH).

23. Acids are easy to recognize because they begin with “H”.
Bases are easy to recognize because they end with “OH”.

24. Bases There are no special rules for naming bases! (they are ionic)
EX: NaOH
Sodium hydroxide

25. Binary Acids Have only two elements.
(hydrogen and a non-metal from the Periodic Table)

26. HCl H3N To Name: Use the prefix “hydro”. 2) Add the suffix “ic”.
Examples:
HCl
H3N
hydrochloric acid
hydronitric acid

27. 1) Start with H+1 2) End with negative (non-metal) ion from
To write formulas:
1) Start with H+1
2) End with negative
(non-metal) ion from
periodic table.
3) “Criss-Cross”.

28. Examples:
Hydroiodic acid
Hydrophosphoric acid HI
H3P

29. Ternary Acids
Have at least three elements:
(H and a polyatomic ion)

30. if “ate” ion, “ic” suffix if “ite” ion, “ous” suffix
To Name:
1) Use NO “hydro” prefix!
2) Add suffix:
if “ate” ion, “ic” suffix
if “ite” ion, “ous” suffix

31. Examples…
HClO3
H2SO3
chloric acid
sulfous acid

32. 1) Start with H+1 2) End with negative (polyatomic) ion.
To write formula:
1) Start with H+1
2) End with negative
(polyatomic) ion.
3) “Criss-Cross”.

33. Examples:
perchloric acid
chlorous acid
HClO4
HClO2

34. 3) Molecular:
Used to name Covalently bonded atoms.
Made up of non-metals only.

35. Molecular Compounds

36. Contain COVALENT bonds.
The same elements can combine in various ways.
Prefixes are used to tell the difference between them.

37. We will only learn BINARY molecular compounds.
Binary = only contains two different elements.
All binary compounds end in “ide”.

38. Prefixes: 1 = mono 6 = hexa 2 = di 7 = hepta 3 = tri 8 = octa
4 = tetra 9 = nona
5 = penta 10 = deca

39. To name: Use prefixes on first atom, except for “mono”.
Always use prefixes on the last atom.
Change ending to “ide”.

40. CO OF2 disulfur trioxide carbon monoxide oxygen difluoride Examples…
S2O3 CO
OF2
disulfur trioxide
carbon monoxide
oxygen difluoride

41. Look at prefixes attached to each element to determine subscript.
To write formulas:
Look at prefixes attached to each element to determine subscript.

42. AsI5 CTe2 P2O3 Examples… Arsenic pentiodide Carbon ditelluride
Diphosphorus trioxide
CTe2
P2O3