From structures to properties

Question 1

why atoms bond

Answer 1

To become stable by filling their outer electron shell (octet rule)

Question 2

Types of chem bonds :

Answer 2

Ionic covalent,polar covalent, and metallic bonds.

Question 2

metallic

Answer 2

electrons move freely

Question 2

Ionic bonding

Answer 2

Attratcs eachother

Question 3

Covalent bonding

Answer 3

Electrons are shared between two non-metals.

Question 4

Polar

Answer 4

Unequal share.Electronegative atoms pulls electrons more.

Question 5

Non-Polar

Answer 5

Equally sharing electrons

Question 6

Lewis Structures

Answer 6

Shows valence electrons as dots and bonds as line.

Question 7

Trigonal Planar (120)

Answer 7

Flat triangle, 3 B.P, 0 L.P

Question 8

VSEPR Theory

Answer 8

Electron pairs repel eachother , so molecules adjust shape tp minimize repulsion.

Question 9

Linear (180)

Answer 9

Straight line, 2 B.P, 0 L.P

Question 10

Tetrahedral (109.5)

Answer 10

3D pyramid , 4 B.P, 0 L.P

Question 11

Pyramidal

Answer 11

3D Pyramid , 3 B.P, 1 L.P

Question 12

Bent (104.5)

Answer 12

Bent Shape, 2 B.P, 2 L.P

Question 13

Intermolecular forces

Answer 13

Weak forces of attraction between molecules.

Question 14

What is IMF’s responsible for?

Answer 14

States,boiling points,surface tension,viscosity, and solubility.

Question 15

Intramolecular forces :

Answer 15

Forces that hold atoms together. (stronger than intermolecular forces)

Question 16

Types on Intra Forces :

Answer 16

Covalent, Ionic and mettallic

Question 17

London dispersion forces (LDF):
present in?
Strength?
Caused by?
Increases with?

Answer 17

• Present in : all molecules, especially non-polar.
• Strength : WEAKEST IMF
• Caused by temporary dipoles due to electrons.
• Increases with larger molecules and more surface area (SA)

Question 18

Hydrogen Bonding :
Present in?
Strength?
caused by?
why the strongest IMF?

Answer 18

• Present in : Molecules where H bonds w/ F,O, or N.
• Strength : STRONGEST IMF
• Caused by strong attractions between H lone pairs.
• Why the strongest : F,O,N are very elctronegative (Highly polar bonds).

Question 18

Dipole - Dipole Forces :
Present in?
Strength?
Caused by?

Answer 18

• Present in : Polar molecules ONLY.
• Strength : Moderate
• Caused by attraction between partial (+) and (-) ends.

Question 19

Isoelectronic substances :

Answer 19

same number of electrons

Question 20

Boiling point : Non-polar

Answer 20

ONLY LDF (USE VESPR)

Question 21

Boiling point : Polar

Answer 21

LDF + D-D FORCES (USE VESPR )

Question 22

Properties of molecular substances :

Answer 22

- Affected by intermolecular forces. - Includes : Solubility,density, surface tension and viscosity.

Question 23

Solubility explanation :

Answer 23

- Polar solutes dissolve in polar solvents. - Hydrogen bonding increases solubility of polar substances.

Question 24

Density explanation :

Answer 24

-stronger IMF = Highr density - Temperature affect : Solids are denser than liquid,but ice is an exception.

Question 25

Viscosity explanation :

Answer 25

- A liquid's resistance to flow Higher viscosity = Thick

Question 26

Surface Tension explanation :

Answer 26

- The skin on the surface of a liquid. - Caused by moelcules pulling on eachother. - Higher intermolecular = Higher surface tension.