Lewis Structures

Question 1

Octet rule

Answer 1

Most atoms form bonds in order to obtain 8 valence electrons
Exceptions- Hydrogen 2, boron 6

Question 2

How to find valence electrons

Answer 2

Down columns

Question 3

Lewis dot structure

Answer 3

A molecular model that uses symbols and bonds to show relative positions of atoms

Question 4

Steps to determine Lewis structure (1)

Answer 4

1-predict draw location
H always end
First element listed is normally central atom

Question 5

Steps to determine Lewis structure (2)

Answer 5

Find number of valence electrons needed and then number they have, subtract the two to find the difference

Question 6

Steps to determine Lewis structure (3)

Answer 6

Use the difference to divide it by two which gives number of bonds

Question 7

Steps to determine Lewis structure (4)

Answer 7

Draw in bonds and then unpaired electrons to central atom

Question 8

Steps to determine Lewis structure (5)

Answer 8

Count number of electrons to check work, should equal number have

Question 9

True or false, most bonds are a blend of ionic and covalent characteristics

Answer 9

True

Question 10

How to find bond type

Answer 10

Difference in electronegativity (subtract)

Question 11

Electronegativity difference number for polar covalent

Answer 11

1.7-.3

Question 12

Electronegativity difference number for no polar covalent

Answer 12

0-.3

Question 13

How to find more polar using periodic table

Answer 13

Bigger difference between the atoms means more polar

Question 14

Non polar covalent bond

Answer 14

Electrons Shared equally
Symmetrical electron density
Usually identical atoms 
( •    •) 
Ex CH

Question 15

Polar covalent

Answer 15

Electronegativity are shared unequally
Asymmetrical electron density
Results in partial charges dipoles
( • Bigger •) neg

Question 16

What is the molecular geometry of covalent molecules is based on

Answer 16

Valence shell electron pair repulsion theory

VSEPR

Question 17

What results in the specific molecular shape and bond angles

Answer 17

Electron pairs arrange themselves to be as far as possible

Question 18

Difference between unshared electrons and shared pairs space

Answer 18

Lone pairs take up more space then shared pairs

Question 19

2 atoms to central, no lone pairs
Shape?
Bond angle?
Example?

Answer 19

Linear
180
Straight line

Question 20

3 atoms to central, 0 lone pairs
Shape?
Bond angle?
Example?

Answer 20

Triangular planar
120
O
O -S-O

Question 21

4 atoms to central, no lone pairs
Shape?
Bond angle?
Example?

Answer 21

Tetrahedral 
109.5
    H
H-C-H
    H

Question 22

3 atoms to central, 1 lone pairs
Shape?
Bond angle?
Example?

Answer 22

Trigonometry pyramidal 
107
     H
H-N-H
     :

Question 23

2 atoms to central, 2 lone pairs
Shape?
Bond angle?
Example?

Answer 23

Bent
104.5
Cl-S::
Cl

Question 24

When is it polar

Answer 24

When no symmetrical (lone pairs or different atoms)

Or uneven sharing of electron pairs due to large difference in electronegativity between two atoms in the bond

Question 25

IMF stands for

Answer 25

Intermolecular forces | Attractive forces between two molecules of the same compound

Question 26

What does polarity depend on

Answer 26

Attraction

Question 27

Which is stronger, polarity or chemical bonds

Answer 27

Chemical bonds

Question 28

What IMF force do all molecules have

Answer 28

London dispersion

Question 29

List weakest to strongest of imf forces

Answer 29

``` Weakest-London dispersion Dipole dipole Hydrogen bonding (Fstrongest) ```

Question 30

London dispersion force

Answer 30

Attraction between two instantaneous dipoles Asymmetrical electron distribution All atoms

Question 31

London dispersion diagram

Answer 31

Two separate oval molecules

Question 32

For London dispersion how to tell a tie

Answer 32

Higher molar mass is a stronger IMF

Question 33

Dipole dipole definition

Answer 33

Attraction between two permanent dipoles | Polar

Question 34

Diagram for dipole dipole

Answer 34

Hydrogen bonded to carbon

Question 35

How to tell a tie from dipole dipole

Answer 35

Greater difference in electronegativity means stronger IMF

Question 36

Hydrogen bonding definition

Answer 36

Attraction between H-FON Polar very strong Not Chem bond

Question 37

How to break a tie for Hydrogen bond

Answer 37

Increase in lone pairs in crease in IMF | FON order, F strongest IMF

Question 38

IMF with phase change | Weaker when

Answer 38

Boiling point is lower Melting point lower Evaporation faster

Question 39

IMF with phase change is stronger when

Answer 39

Boiling point higher Melting point high Evaporation slower