1. CHEMICAL NAMES & FORMULAE
Chapter 9

2. Ions It’s all about the electrons! Lose electrons  positive ion
Cation
Gain electrons  negative ion
Anion

3. Chemical formulae Ions combine to form compounds (cmpds)
1 or more metals = “formula unit”
2 nonmetals = “molecule”
Law of Definite Proportions
Masses of elements combining always same regardless of #
A lot or a little, ratio always the same!
Law of Multiple Proportions
Whole number ratios; no fractions!
Ex: H2O vs. H2O2
if mass of H is equal in both, the ratio mass of O is equal to #
H2O, not H2.756O.8975

4. Law of Multiple Proportions
Carbon reacts with oxygen to form two compounds. Compound A contains 2.41 g of carbon for each 3.22 g of oxygen. Compound B contains 6.71 g of carbon for each 17.9 g of oxygen. What is the lowest whole-number ratio of carbon that combines with the given mass of oxygen?

5. To Solve: Cmpd A: 2.41 g C/3.22 g O = .748 g C/1.00 g O
Cmpd B: 6.71 g C/17.9 g O = .375 g C/1.00 g O
.748 g C (from A)/.375 g C (from B) = ~ 2
2:1 ratio of carbon to oxygen

6. Ion Writing - Practice Gain or lose electrons Calcium Magnesium
Chlorine
Oxygen
Sulfur
Iron loses 3 electrons
Calcium loses 2
Oxygen gains 2
Chlorine gains 1
Nickel loses 2

7. Intro To Bonding Molecules & compounds (cmpds)
Diatomic Molecule = one kind of element stuck together (O2)
diatomics = Cl I F H O Br N
high melting, boiling points; very stable
Molecular compound = compounds made of nonmetals stuck together (2+ elements together)
low melting, boiling points; more easily broken

8. Ions/Ionic Cmpds
Ions = atoms/groups of atoms with a charge due to gain or loss of e-
occurs because of stability (tendency to lose/gain due to what it is exposed to)
losing e- creates positive charge – cation
name of ion stays the same as element
gaining e- creates negative charge – anion
name of ion ends in –ide
Reduce subscripts!
Ex: CuS, not Cu2S2

9. Polyatomic Ions – p. 147 Memorize name, formula, and charge: Acetate
Nitrite
Nitrate
Cyanide
Hydroxide
Permanganate
Hypochlorite
Chlorite
Chlorate
Perchlorate
Oxalate
Sulfite
Sulfate
Carbonate
Chromate
Dichromate
Thiosulfate
Peroxide
Phosphate
Ammonium
Iodate

10. Ionic Cmpds - Joining Ions
“Swap and Drop”; total charge is neutral
solid at room temp
high melting point
example: Na+1 and Cl-1 becomes NaCl; Ca+2 and Cl-1 becomes CaCl2 ; Ca+2 and O-2 becomes CaO

11. Binary Ionic Cmpds Cobalt iodide Zinc sulfide Calcium phosphide
Potassium chloride
Sodium oxide
Calcium oxide – careful!

12. Ionic Formulae Sodium sulfide Calcium chloride Magnesium phosphate
Sodium perchlorate
Silver nitrate
Potassium hypochlorite

13. Special Naming – Roman #
Elements that require roman numerals – p. 144
Memorize:
Copper (I or II)
Iron (II or III)
Lead (II or IV)
Tin (II or IV)
Chromium (II or III)
Cobalt (II or III)

14. Molecular Cmpds

15. Molecular Cmpds - nonmetals
Special naming rule – never reduce!
Use prefixes to indicate # of atoms
Mono (anion only) Di
Tri
Tetra
Pent
Hex
Hept
Oct
Non
Examples:
S2F6
CO2
N2I3
H2O

16. Acids – Begin with Hydrogen!

17. Acid Naming Binary Acids – prefix hydro_____ ic acid
HCl
H2S
H3N
Ternary Acids - __________ ic acid for -ates
H2SO4
HNO3
H3PO4
__________ ous acid for -ites

18. Acid Formula Writing Acetic acid Nitric acid Carbonic acid
Sulfuric acid
Hydrochloric acid
Hydrophosphoric acid
Hydronitric acid

19. Review of Naming Ionic – reduce! Molecular – never reduce! Binary
-ide
Ternary
-ate, -ite
Polyatomic ions
Roman numerals
Molecular – never reduce!
Prefixes
Acids
Binary  hydro___ic acid
Ternary  _____ic acid for –ate
 ___ ous acid for -ite

20. Review of Writing 1> metals? Determine charge Swap and Drop Reduce!
Oxidation number
Roman numerals
Positive element 1st
Keep polyatomics together
Swap and Drop
Reduce!
Nonmetals only?
Prefixes reflect #
Hydrogen 1st?
Binary = 2 elements
Ternary = polyatomic
-ate = ic acid
-ite = ous acid
Don’t reduce!