Chp 6 Liquids and Solids [COMPLETE]

Question 1

what are the intramolecular forces?

Answer 1

metallic bonding, ion-ion bonding, and covalent network bonding

Question 2

what are the intermolecular forces, from strongest to weakest?

Answer 2

hydrogen bonding, dipole-dipole, dispersion forces (london or van der waals)

Question 3

what is hydrogen bonding?

Answer 3

when a molecule has a hydrogen atom that is bonded to a nitrogen, oxygen or fluorine (H-N, H-O, H-F). partial neg connected to partial pos charge

Question 4

why is hydrogen bonding very strong?

Answer 4

N, O, and F are so much larger and more electronegative than H, tightly knit

Question 5

what are dipole dipole forces similar to?

Answer 5

hydrogen bonding; have the partial neg connect to partial pos, just not on N, O, or F molecules

Question 6

what are dipole dipole forces?

Answer 6

when a molecule w a polar bond (significant electronegativity diff) causes one atom to have partial neg and the other atom to have partial pos charge, and cluster w another similar molecule; aka the forces between these two clusters

Question 7

what do dipole dipole forces only apply to?

Answer 7

polar, non-ionic molecules that are not H bonded to N, O, or F

Question 8

what are dispersion forces?

Answer 8

forces that occur in all molecules in which temporary partial pos and partial neg attractions can exist

Question 9

what forces will a non polar molecule have that does not have hydrogen bonding or dipole dipole forces?

Answer 9

dispersion forces

Question 10

if two molecules exist with the same intermolecular forces, the larger molecule (higher molecular weight) will have what?

Answer 10

stronger force and a higher boiling point

Question 11

what are intermolecular forces responsible for?

Answer 11

a molecules boiling point

Question 12

definition: intermolecular forces

Answer 12

forces that attract molecules to each other

Question 13

what are the characteristics of a strong intermolecular force?

Answer 13

high boiling point, high viscosity, high surface tension, low vapor pressure

Question 14

↑ intermolecular force = _ boiling point? _ heat of vaporization?

Answer 14

↑ boiling point, ↑ heat of vaporization

Question 15

↑ intermolecular force = _ viscosity?

Answer 15

↑ viscosity

Question 16

what causes surface tension?

Answer 16

H2O molecules at the top of a body of water experience downward and side-to-side attraction from neighboring molecules; creates a thin film on water surface

Question 17

↑ intermolecular force = _ surface tension?

Answer 17

↑ surface tension

Question 18

when does boiling occur?

Answer 18

when vapor pressure equals or exceeds atmospheric pressure

Question 19

↑ intermolecular force = _ vapor pressure?

Answer 19

↓ vapor pressure

Question 20

↓ atmospheric pressure = _ boiling point?

Answer 20

↓ boiling point

Question 21

↑ atmospheric pressure = _ boiling point?

Answer 21

↑ boiling point

Question 22

what are the four classes of solids?

Answer 22

metallic solids, ionic solids, covalent-network solids, and molecular solids

Question 23

what are metallic solids held together by and what are its properties?

Answer 23

held by a delocalized “sea” of shared electrons, flowing around nuclei “islands”; properties include conductive, variable hardness, and high melting point

Question 24

what are ionic solids held together by and what are its properties?

Answer 24

held by the strong attraction between cations and anions; properties non-conductive, hard, brittle and high melting point

Question 25

what are covalent-network solids held together by and what are its properties?

Answer 25

held by an extended network of covalent bonds; properties include non-conductive, hard, high melting point

Question 26

what are molecular solids held together by and what are its properties?

Answer 26

held by the intermolecular forces; properties include non-conductive, soft, low melting point

Question 27

what are unit cells?

Answer 27

small repeating units stacked over and over that make up an entire solid

Question 28

how many atoms are in a simple cubic cell?

Answer 28

1

Question 29

how many atoms are in a body-centered cubic?

Answer 29

2

Question 30

how many atoms are in a face-centered cubic?

Answer 30

4

Question 31

solid ---> liquid

Answer 31

fusion

Question 32

liquid ---> gas

Answer 32

vaporization

Question 33

solid ---> gas

Answer 33

sublimation

Question 34

fusion, vaporization, and sublimation all:

Answer 34

consume heat (endothermic +∆H) create disorder (positive entropy +∆S)

Question 35

gas ---> liquid

Answer 35

condensation

Question 36

liquid ---> solid

Answer 36

crystallization

Question 37

gas ---> solid

Answer 37

deposition

Question 38

condensation, crystallization, and deposition all:

Answer 38

produce heat (exothermic -∆H) create order (negative entropy -∆S)

Question 39

↑ boiling point = _ vapor pressure

Answer 39

↓ vapor pressure

Question 40

↑ vapor pressure = _ volatility

Answer 40

↑ volatility

Question 41

↑ vapor pressure = _ temperature

Answer 41

↑ temperature

Question 42

what is a phase diagram?

Answer 42

graphical way to show pressures and temperatures at which a substance will exist as either a solid, liquid, or gas, or in some kind of equilibrium

Question 43

what is the critical point of a phase diagram?

Answer 43

upper right point; beyond this, liquids and gases are indistinguishable

Question 44

what is the triple point of a phase diagram?

Answer 44

left middle point; point where all three phases are in equilibrium

Question 45

what does the line of equilibrium between solid and liquid signify:

Answer 45

where solid/liquid can exist at the same time and where phase change occurs

Question 46

what phase change occurs when you increase the temperature at a high enough pressure?

Answer 46

fusion (solid to liquid)

Question 47

what phase change occurs if you increase the temperature but the pressure is not high enough?

Answer 47

sublimation (solid to gas)

Question 48

how long does the solid/liquid line continue on?

Answer 48

forever

Question 49

(most compounds) gas (add pressure) ___ liquid (add pressure) ___ solid

Answer 49

-->, -->

Question 50

(for water) gas (add pressure) ___ liquid ___ (add pressure) solid

Answer 50

-->, <--

Question 51

in what state is water more dense?

Answer 51

as a liquid

Question 52

why is water is more dense as a liquid than as a solid?

Answer 52

lattice arrangement of water molecules causes more space to be between them

Question 53

how is water's phase diagram different from a normal one?

Answer 53

solid/liquid line leans to the left; negative slope; meaning if temperature is low enough and you add pressure, gas can go straight to solid without becoming liquid and adding more pressure will turn solid to liquid (adding more pressure would not turn a solid to liquid in a normal phase diagram)

Question 54

what does the negative slope of the water phase diagram mean?

Answer 54

the liquid phase of water is more dense than solid

Question 55

what is distillation?

Answer 55

process by which miscible liquids are separated by boiling point

Question 56

what is filtration?

Answer 56

separation of solids from liquids by pouring through a filter

Question 57

what is decantation?

Answer 57

separation of liquids from solids by pouring the liquid carefully off the top

Question 58

describe a chemical compound

Answer 58

a substance composed of different elements in fixed proportions

Question 59

what is a pure element?

Answer 59

a substance that cannot be decomposed into simpler species