1. Write the formula for magnesium chloride.

2. Draw the dot structure for magnesium chloride.

Day 2 3-30

Valence-Shell, Electron-Pair Repulsion

VSEPR theory

Repulsion between sets of valence-level electrons, causes them to be oriented as far apart as possible

What do electrons do to other electrons?

VSEPR theory – in a small molecule, the pairs of valence electrons are arranged as far apart from each other as possible

1. Draw the dot structure for CH4.Day 3 4-2

Draw the Lewis Dot Structures for the following:

NaCl, O2, CO2, H2O, BCl3, NH3, CH4

Build:

O2

CO2

*BCl3

CH4

*NH3

H2O

Linear

Trigonal planar

Tetrahedral

Pyramidal Bent

Reds = oxygen short “bonds” = single bonds

Blacks = carbon long “bonds” = double bonds

Whites = hydrogen

Greens = chlorine

Blue = nitrogen

1st & 5th pd stopped

3rd pd stopped

Number of atoms bonded to central atom

# of lone pair electrons

Shape Example(s)

1 0, 1, 2, 3 _________ NaCl, O2

2 0 _________ CO2

2 2 _________ H2O

3 0 __________________

BCl3

3 1 _________ NH3

4 0 _________ CH4

LINEAR

LINEAR

BENT

TRIGONAL

PLANAR

PYRAMIDAL

TETRAHEDRAL

Carbon compounds form 3 shapes, what are they?

WHY? ______________________

____________________________

____________________________

For #s 58 + 60 on pages 256-257 DO DOT STRUCTURES AND SHAPES FOR BOTH!!!

Read Section 8.4 (pages 261-264 AND complete #s 61, 63, 64, 66 (only molecular shape not hybrid orbitals) AND # 60 = an optional bonus –

must be correct

Going back: How did we name orbitals?

2p

Energy level

Shape

As atoms come together and bond, orbitals come together, overlap, and mix … hybridization

As atoms come together and bond, orbitals come together, overlap, and mix … hybridization

Hybrid orbitals – mixed orbitals – combo. of properties of the atomic orbitals that formed them

Polar bonds?

HBr2.8 2.1

Polar Covalent

Intermolecular ForcesForces of attraction between molecules

Intramolecular ForcesForces of attraction within molecules

OH

H

Intermolecular ForcesForces of attraction between molecules

Hydrogen Bonding

OH

H(-) (+)O

H

H(-) (+) O

H

H(-) (+)

PERIODS 3 & 6 – 2-18

Hydrogen bonding is a direct result of water’s polar nature and leads to …

Water sticking to water

Water sticking to something else

… cohesion … adhesion

Does a polar bond mean you have a polar molecule?

CO2 – Polar bonds? Polar molecule?

Does a polar bond mean you have a polar molecule?

Polar molecules unequal charge

distribution …2 factors are molecular shape and bonds (polar

vs. nonpolar)

Polar bond(s)?

Polar molecule?

HCl

SiS2

BCl3

NH3

PERIODS 1 & 5 – 2-18

Read section 12.2 AND complete the section review on page 414

#s 14-16

Linear

VSEPR theory

Intermolecular force

Cohesion

H2SO4

Hydrogen bonding

Bent

Adhesion

Intracellular

Octet rule

Read section

Number of atoms bonded to central atom

# of lone pair electrons

Shape Example(s)

1 0, 1, 2, 3

_________

NaCl, O2

2 0

_________

CO2

2 2

_________

H2O

3 0 _________

_________

BCl3

3 1

_________

NH3

4 0 _________

CH4

HBr2.8 2.1

Polar Covalent

OH

H

Intracellular

OH

H(-) (+)O

H

H(-) (+)

Intercellular

OH

H(-) (+)O

H

H(-) (+) O

H

H(-) (+)