Chapter 6.1 Introduction to Chemical Bonding Molecule – smallest

electrically neutral unit of a substance that still has the properties of the substance

Made up of two or more atoms

Molecular Compound Compounds

composed of molecules made up of different atoms

Molecular Compounds Usually low melting

and boiling points Usually liquids or

gases at room temperature

Usually made up of two or more nonmetals

Ions Atoms or groups of

atoms that have a positive or negative charge

Forms when an electron is lost or gained

Cation Any atom or group

of atoms that has a positive charge

Lose electrons Usually Metals

Anion Any atom or group

of atoms that has a negative charge

Gains electrons Usually Nonmetals

Ionic Compounds Compound

composed of anions and cations

Usually a metal cation and a nonmetal anion

Characteristic Molecular Compound

Ionic Compound

Representative Unit

Molecule Formula Unit

Type of Elements

Nonmetals Metal and Nonmetal

Physical State Solid, Liquid or Gas

Solid

Melting Point Low below 300 degrees Celsius

High above 300 degrees Celsius

Chapter 6.2 Representing Chemical Compounds Chemical Formulas Molecular Formulas Formula Units Laws of Proportions

Chemical Formulas Show the kinds and

numbers of atoms in the smallest representative unit of the substance

Monatomic Represent their

chemical formula by writing their symbol

Copper – Cu Helium - He

Diatomic If the molecules of

an element have more than one atom, use a subscript to indicate how many

Hydrogen – H2

Oxygen – O2

The Seven Diatomic Elements You must Memorize Hydrogen – H2

Fluorine – F2

Oxygen – O2

Nitrogen – N2

Chlorine – Cl2 Bromine – Br2

Iodine - I2

Molecular Formulas Shows the kinds

and numbers of atoms present in a molecule of a compound

Does not show anything about the structure

Ammonia

NH3

Formula Units (Ionic Compounds) Does not represent

a molecule No separate

molecular units Arranged in an

orderly pattern

Formula Unit Lowest whole

number ratio of ions in a compound

NaCl 1:1 MgCl2 1:2

The Law of Definite Proportions In samples of any chemical compound, the

masses of the elements are always in the same proportion.

The Law of Multiple Proportions Whenever two elements form more than one

compound, the different masses of one element that combine with the same mass of the other elements are in small whole number ratios.

Chapter 6.3 Ionic Charges Monatomic Ions Polyatomic Ions

Monatomic Ions Ions consisting of

only one atom

Monatomic Ions – Cations Group 1A ions all

have a 1+ charge Group 2A ions all

have a 2+ charge Group 3A ions all

have a 3+ charge Only for metals

Monatomic Ions – Cations

? the group number from 8 to get number of the charge

Monatomic Ions - Anions Group 7A ions all

have a 1 – charge Group 6A ions all

have a 2 – charge Group 5A ions all

have a 3 – charge Only for nonmetals

Monatomic Ions - Anions Subtract group

number from 8 to get number of the charge

Naming ions with more than one oxidation numbers Stock System Use a roman

numeral after the symbol to indicate charge

Iron – Fe2+ - Iron (II) ion Fe3+ - Iron (III) ion

Polyatomic Ions Tightly bonded

group of atoms that behave as a unit and carry a charge

Sulfate – SO42-

Polyatomic Ions Most end in “ite” or

“ate” Look at table E Three exceptions

Ammonium Cyanide Hydroxide

Polyatomic Ions “ite” indicates one

less of oxygen “ate” indicates one

more of oxygen Does not tell how

many oxygens

Chapter 6.4 Ionic Compounds Writing Formulas Naming Binary

Compounds Ternary Ionic

Compounds

Anions Change ending to

“ide” Oxygen – Oxide Sulfur - Sulfide

Writing Formulas for Binary Ionic Compounds Binary Compound –

composed of two elements

The positive charge of the cation must balance the negative charge of the anion.

Writing Formulas for Binary Ionic Compounds The total net charge

must equal 0. Potassium Chloride

K+ and Cl-

KCl

Rust - Iron(III) Oxide Ions - ? Formula ?

Crisscross method Rust Iron(III) Oxide

Fe3+ and O2-

Naming Binary Ionic Compounds Cation first, anion

second Make sure charges

balance, if not, use subscripts to balance

If the cation has more than one oxidation number, use roman numerals to indicate charge (ONLY Positive)

Ternary Ionic Compounds Contains atoms of

three different elements

Calcium Carbonate CaCO3

Ternary Ionic Compounds “ate” or “ite” ending

indicates a polyatomic anion containing oxygen

Calcium Nitrate Ca2+ , NO3

-

Ca (NO3)2

Chapter 6.5 Molecular Compounds and Acids Binary Molecular

Compounds Naming Common

Acids

Binary Molecular Compounds Composed of two

nonmetallic elements

Prefixes are used to indicate the number of each atom present

Binary Molecular Compounds

Prefixes

Prefix Number

Mono- 1

Di- 2

Tri- 3

Tetra- 4

Penta- 5

Hexa- 6

Hepta- 7

Octa- 8

Nona- 9

Deca- 10

Binary Molecular Compounds All end with “ide” Drop the vowel at

the end of the prefix if the element begins with a vowel CO Carbon Monooxide Carbon Monoxide

Binary Molecular Compounds If the first element

has just one atom, drop the mono- CO Monocarbon

monoxide Carbon monoxide

Binary Molecular Compounds Tetraiodine

nonoxide ??

N20 ??

Naming Common Acids Compounds that

produce hydrogen ions when dissolved in water

Anions connected to as many H+ ions to make the molecule neutral

Naming Common Acids HCl

Hydrochloric Acid H2SO4

Sulfuric Acid HNO3

Nitric Acid HC2H3O2

Acetic Acid H3PO4

Phosphoric Acid H2CO3

Carbonic Acid

Chapter 6.6 Summary of Writing and Naming

PxQy

P = Hydrogen

P = Hydrogen