1. Chemical Compounds
Honors Chemistry

2. 3 Types of Formulas
Empirical: Smallest whole-number-ratio of atoms or ions in a compound
Ex. CH2 NH3
Molecular: Tells you the actual number of atoms of an element in a compound
Ex. C2H4 N2H6
Structural: Indicates how the atoms are bonded to each other

3. How does the mole relate to compounds?
REMEMBER
Atoms are too small to count or mass individually.
It is easier to count many or mass many.
amu gram
(atomic scale) (macroscopic scale)
mole
atoms, ions, molecules, or formula units
Molar Mass = mass, in grams, per 1 mole of a substance units = grams/mole (g/mol)
Example: the molar mass of H2O is
18.0 g/mol

4. % Composition = (part/whole) x 100
Molecular formulas and molar masses are used to determine Percent Composition
Definition: percentage, by mass, of each element
in a compound
% Composition = (part/whole) x 100
Problems
Calculate the % composition of NaCl
% Na:
% Cl:
39.3% Na
60.7% Cl

5. molar mass of anhydrate + x(molar mass of water)
Percent Composition of Hydrate Definition: A hydrate is an ionic compound with water embedded in it.
Calculate the % water in a hydrate, Mg3(PO4)2 . 6H2O.
molar mass of hydrate =
molar mass of anhydrate + x(molar mass of water)
% water =
370.9 g/mol Mg3(PO4)2 . 6H2O
29.1% H2O

6. How can you identify different types of compounds?
Type of Compound Identification
Ionic Begins with a metal
Covalent Begins with a nonmetal
Acid Begins with a hydrogen and is aqueous
Hydrate Ionic Compound and Water

8. Ionic Compounds Made from a positively and negatively charged ion
Overall charge of the compound is zero
Types of Ionic Compounds
Binary
Ternary

9. Binary Compounds: Composed of two monatomic ions
Primary Rules for Charges: YOU MUST KNOW THESE RULES
1 or IA +1
2 or IIA +2
13 or IIIA +3
15 or VA -3 in binary compounds with metals, H, or NH4+
16 or VIA -2 in binary compounds with metals, H, or NH4+
17 or VIIA -1 in binary compounds with metals, H, or NH4+

10. NaCl Fe2S3 iron(II) sulfide
Ionic Compounds – look at charges; roman numerals needed for elements with more than one charge (polyvalent)
a. Binary Compounds – only monatomic ions in compound
sodium chloride
iron(III) sulfide
FeS
NaCl
Fe2S3
iron(II) sulfide

11. Ionic Compounds hydrogen fluoride aluminum chloride
Binary Compounds
HF(g)
AlCl3
Cr2O3
hydrogen fluoride
aluminum chloride
chromium(III) oxide

12. Ionic Compounds
Ternary Compounds – contain 1/more polyatomic ions in compound
sodium carbonate
chromium(III) oxalate
ammonium sulfate
Na2CO3
Cr2(C2O4)3
(NH4)2SO4

13. Note for polyatomic ions:
Ionic Compounds
Ternary
Co3(AsO4)2
CuSO3
Note for polyatomic ions:
-ate vs. –ite
per- and hypo-
cobalt(II) arsenate
copper(II) sulfite

14. Ionic Compounds Mg(OH)2 CaSO4 (NH4)3PO4 magnesium hydroxide
calcium sulfate
ammonium phosphate
Mg(OH)2
CaSO4
(NH4)3PO4

15. 1 extra oxygen ClO4-1 perchlorate ClO3-1 chlorate 1 less oxygen
Anion
Description
Example
1 extra oxygen
ClO4-1
perchlorate
per_____ ate
ClO3-1
chlorate
the most common form
_______ate
1 less
oxygen
ClO chlorite
_______ ite
2 less
oxygens
ClO-1
hypochlorite
hypo_____ ite

16. Now try these… SO3-2 IO4-1 PO3-3 HSO3-1 sulfite periodate phosphite
bisulfite
SO3-2
IO4-1
PO3-3
HSO3-1

17. Check for Understanding
MgH2
magnesium hydride
calcium acetate
FeS2O3
SnI4
Ca(CH3COO)2
iron (II) thiosulfate
tin (IV) odide

18. Molecular Compounds – formed between 2 nonmetals
*Use prefixes
mono = 1 hexa = 6
di = 2 hepta = 7
tri = 3 octa = 8
tetra = 4 nona = 9
penta = 5 deca = 10
Binary Compounds: only 2 elements in the compound; use prefixes and –ide ending
CCl4
N2O5
carbon tetrachloride
dinitrogen pentoxide

19. More Practice dihydrogen monoxide nitrogen tetrabromide S2O6 H2O NBr4
disulfur hexoxide

20. Hydrates – ionic compound with water bonded in its structure
anhydrate . xH2O
anhydrate  ionic compound
add prefix to indicate # of water molecules
CuSO4 . 5H2O
copper(II) sulfate pentahydrate

21. Acids – compounds that produce hydrogen ions in water
Mineral Acids
Binary Acids
1st word: prefix = hydro
root formed from anion
suffix –ide changed to -ic
2nd word: acid
HCl(aq)
HBr(aq)
hydrochloric acid
hydrobromic acid

22. B. Oxyacids 1st word: root from anion Suffix ate changed to ic
Suffix ite changed to ous
**Exceptions: if you have sulf or phos as roots, change the root to sulfur or phosphor
2nd word: acid
HNO3
HNO2
phosphorous acid
Nitric acid
Nitrous acid
H3PO3

23. 2. Organic Acids 1st word: root formed from anion
Suffix ate changed to ic
2nd word: acid
C6H5COOH(aq)
or HC6H5COO(aq)
acetic acid
Benzoic acid
HCH3COO
or CH3COOH

24. Common Acids to Know HCl H2CO3 HClO4 H2SO4 H3PO4 HNO3
hydrochloric acid
HCl
H2CO3
HClO4
H2SO4
H3PO4
HNO3
CH3COOH = HC2H3O2
carbonic acid
perchloric acid
sulfuric acid
phosphoric acid
nitric acid
acetic acid

25. Salts
Ionic compound composed of a cation (positive ion) and an anion (negative ion) from an acid
NaCl
CaSO4
NaHCO3
NaHSO3