Notes 

Chapter 8 Notes(p. 195-234)

Read page 232 for the five facts.

Covalent bond=

Results when atoms share Electrons.

Molecule=

A Compound in which electrons are shared.

Lewis structure=

Electron dot diagram for valence electrons.

Sigma bond=

Single covalent bond.(e- are centered between two atoms.)

Pi bond=

The bonds formed after a sigma bond, in which orbitals overlap and share bonds.

-Double covalent bond=

This results when two pairs of electrons are shared between atoms.

-Triple covalent bond=

This results when three pairs of electrons are shared between atoms.

Endothermic reaction=

Results as heat is pulled in from the surroundings.

Exothermic reaction=

Results as heat is released to the environment.

*cold is the absence of heat.

1=Mono

2=Di

3=Tri

4=Tetra

5=Penta

6=Hexa

7=Hepta

8=Octa

9=Nona

10=Deca

Naming covalently bonded compounds.

1. List the prefix that indicates the subscript of the first element.

2. Write the name of the first element.

3. List the prefix that indicates the subscript of the second element.

4. Write the name of the second element with the -ide ending.

C5Cl8

Pentacarbon Octachloride

Do NOT use mono for the first element!

Rules for Naming Acids(Anions end in ide)

Binary acids

1. Write hydro

2. Write the root word of the anion.

3. Write -ic and acid.

Ex. HBr

Hydrobromic Acid

Acids that contain Oxygen

Anions end in –ate

1. Write the root of the polyatomic anion

2. Write ic and acid.

EX. H3PO4

Phosphoric Acid

Anions end in –ite

1. Write the root of the polyatomic anion

2. Write ous and acid.

EX. HNO2

Nitrous Acid

Structural Formula=

This uses letter symbols and bonds to show the relative position of the  atoms.

Resonance=

A condition that occurs when more than one structure is valid.

Coordinate covalent bond=

Forms when one atom donates both electrons to the shared bond.

Exceptions to the Octet/Duet Rule

Family 3A may form three bonds.

Family 5 A may form five bonds.

VSEPR model=

(Repulsion model) This model is based on minimizing the repulsion of shared and unshared pairs of electrons.

VSEPR---Valence Shell Electron Pair Repulsion

Angles and geometric shape for:

X2 =Linear 1800

X1Y2 =Linear 1800

3A1Y3 =Trigonal planar 1200

5A1Y3 =Trigonal pyramidal 107.30

X1Y4 =Tetrahedral 109.50

X1Y5 = Trigonal Bipyramidal 900   1200

X1Y6 =Octehedral   900

X2Y1 =Bent 104.50

Hybridization=

A process in which atomic orbitals mix and form new identical hybrid orbitals.

-Electron Affinity=

The measure of the tendency of an atom to attract an electron.

-Electronegativity=

The relative affinity of electrons by an atom.

Characteristics of bonds

•           >1.7 Mostly ionic

•         0.4-1.7 Polar Covalent

•         0<0.4  Mostly Covalent

•         0 Nonpolar Covalent

Ex. What type of bond forms when Boron and Chlorine combine.

BCl3

3.16-2.04=1.12 Polar Covalent

-Nonpolar covalent=

Equal sharing of electrons by the atoms.

-Polar covalent=

Unequal sharing of electrons by the atoms.

-Ionic bonds=

A transfer of electrons from one atom to another.

Forces on atoms and molecules

*Intramolecular forces-

Attractions within the same molecule that holds the molecule together.

*Intermolecular forces-

The attractions from one molecule to another.

*Vander Waals forces= 

The weakest attractions between all compounds.(Inter)

*London dispersion forces-

Forces that exist between noble gases and covalently bonded molecules.(Inter)

*Dispersion forces= 

Weakest molecular attractions, which is caused by e- motions. The greater the # of e-, the greater the dispersion forces(Intra)

                more e- = more solid

                less e- = more gaseous

*Dipole interaction= 

This results when polar molecules attract one another.(Inter)

*a) Instantaneous dipole-

This results when electrons move about the molecule. (Causes one end to be slightly negative and the other to be slightly positive.)

*b) induced dipole-

An atom or molecule that develops poles due to another atom or molecule near it.

*Hydrogen bonds= 

Attractive forces in which Hydrogen in a bond is weakly bonded to an unshared e- pair.(Inter)

Better Acid Rules

No Oxygen present

-ide use hydro root word ic and acid

Oxygen present

-ite goes with root word ous and acid

-ate goes with root word ic and acid