VSEPR theory chapter Flashcard

VSEPR Theory

Valence Shell Electron Pair Repulsion Theory- the repulsion between electron pairs cause molecular shapes to adjust so that the valence-electron stay as far apart as possible.

Shape:

 

H-O-H

Linear Triatomic
Shape[image]
Triagonal Planar

Shape:

O:

H   H

Bent Triatomic
Shape[image]
Pyramidal
Shape[image][image]
Tetrahedral
Shape[image]
Triagonal Bipyramidal

Shape[image]

Octahedral
Linear Properties (5)

A2 or AX (diatomic)

AX2 (triatomic)

1 or 2 shared pairs

No unshared pairs on central atom

Bond angle: 180o

Bent Properties (4)

AB2

2 shared pairs

Some unshared pairs on central atom

Bond angle: less than 180o

Triagonal Planar Properties (4)

AX3

3 shared pairs

No unshared pairs on central atom

Bond angle: 120o

Triagonal Bipyramidal propertes (4)

AX5

5 unshared pairs

No unshared pairs on central atom

Bond angle: 90o and 120o

Octahedral properties (4)

AX6

6 unshared pairs

No unshared pairs on central atom

Bond angle: 90o

Polar Bond properties (2)

Uneven charge distribution difference in electronegatibity (0.3- 1.7)

2 different atoms in a bond

Nonpolar bond properties (3)

Equal charge distribution

no difference in electronegatibity

USameU atoms in a bond

Polar Bond examples

H-Cl

Mg- O

C-F

S-Br

Nonpolar Bond Examples

H-H

Cl-Cl

S-S

C-C

If a molecule is symmetrical then it is (polar/nonpolar)
Nonpolar
If a molecule is not symmetrical, then it is (polar/nonpolar)
Polar
Diatomic elements definition
Elements that are always found in pairs.

List Diatomic elements

Oxygen

Nitrogen

Flourine

Chlorine

Bromine

Iodine

Hydrogen

located in the shape of a seven on the periodic table ecept for hydrogen

"Like dissolves like" meaning

Polar solutions dissolve polar materials

Nonpolar solutions dissolve nonpolar materials

Polar solutions do not dissolve nonpolar materials

Intermolecular Forces

Van der Waals forces

between one molecule and its neighbor

Dipole- dipole interactions (3)

Between polar molecues

Positive end of one molecule attracts negative end of another molecule

Gives polar molecules higher poiling points than nonpolar molecules

London dispersion forces (4)

Between nonpolar molecules

Most common force

Very weak force

E-movement causes temporary dipole

Note: All molecules have _____, but nonpolar molecules ONLY have ______!
London Forces (omit if first)
Hydrogen bonding (3)

Must have H bonded to N, O, or F

Strongest intermolecular force

Gives water special properties

Special Properties of Water

These properties make our life on earth possible!

(7)

Low melting point

High boiling point

High heat of vaporation

Surface tension

Capillary action

Solid is less dense than liquid

Universal solvent

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