Week Ten

Question 1

Properties of liquids

Answer 1

strong inter molecular
free to move
cannot expand or contract significantly

Question 2

Surface tension

Answer 2

measure of resistance of a liquid to an increase in its surface area

Question 3

attraction of liquids on surface

Answer 3

net attractive forces that pulls them towards the interior of the liquid

Question 4

middle of liquids - attraction

Answer 4

no net pull in any direction in the middle

Question 5

Spherical shape of water

Answer 5

have less surface area so water is attracted to this shape

Question 6

Forces that molecules in contact with surface have

Answer 6

adhesion

cohesion

Question 7

adhesion forces

Answer 7

attract molecules in liquid to walls of container

Question 8

cohesion forces

Answer 8

attract molecules in liquid to one another

Question 9

Meniscus

Answer 9

curves surface of liquid, formed by adhesion and cohesion forces

Question 10

strength of forces

Answer 10

adhesion forces are stronger than cohesive

Question 11

Capillary action

Answer 11

upward movement of water against gravity

due to adhesion forces between water and oxygen

Question 12

Viscosity

Answer 12

liquids resistance to flow

greater the viscosity, slower the liquid pours

Question 13

What affects viscosity

Answer 13

combination of molecular shape and intermolecular forces

affected by temp

Question 14

Viscosity vs temp

Answer 14

decreases as temp increase due to higher kinetic energy

Question 15

Vapour pressure

Answer 15

the pressure that occurs when both the gas phase and liquid phase are happening at same time

Question 16

vapour pressure in closed container

Answer 16

partial pressure increases as molecules enter gas phase

Question 17

vapor pressure in open container

Answer 17

will continually lose molecules to gas phase until fully evaporated

Question 18

Vapor pressure vs temp

Answer 18

at high temp, amount of molecules that can leave phases increases

Question 19

liquid kinetic energy

Answer 19

have energy kinetic energy to move around within liquid phase

Question 20

What affects vapour pressure

Answer 20

strength of intermolecular forces and temp

Question 21

Vapor pressure - boiling liquid

Answer 21

when vapor pressure equals outside pressure, liquid will boil

Question 22

Low pressure - vapor pressure - boiling

Answer 22

boiling point lower, pressure easily reached

Question 23

high pressure - vapor pressure - boiling

Answer 23

boiling point increases,

Question 24

Magnitude of forces in solids

Answer 24

forces range from large to small

can be bound by various attractive forces

Question 25

intermolecular forces

Answer 25

molecular solids

Question 26

covalent bonds

Answer 26

network solids

Question 27

delocalised bonds

Answer 27

metallic solids

Question 28

electrostatic bonds

Answer 28

ionic solids

Question 29

Molecular solids

Answer 29

aggregates of molecules are bound by dispersion, dipolar, hydrogen bonding or combination

Question 30

Network solids

Answer 30

have high melting points held by covalent bonds bonding pattern determines properties

Question 31

Metallic solids

Answer 31

array of metal atoms embedded in mobile valence electrons ductile and malleable range of properties properties determined by position on periodic table and number of valence electrons

Question 32

Ionic solids

Answer 32

contain cation and anions strongly attracted to each other by electrostatic forces determined by charges

Question 33

temp during phase change

Answer 33

remains same

Question 34

what must happen for temp to change during phase change

Answer 34

substance must be completely changed

Question 35

phase changes - energy

Answer 35

require that energy is either supplied or removed from substance

Question 36

Phase change

Answer 36

transition of substance from one phase to other | depends on temp, pressure, magnitude of bonds and intermolecular forces

Question 37

molar enthalpy of melting

Answer 37

for solid to liquid | heat needed to melt 1 mole of substance at normal melting point

Question 38

Molar enthalpy of vaporisation

Answer 38

for liquid to gas | heat needed to vaporise 1 mole of substance at normal boiling point

Question 39

Molar enthalpy of sublimation

Answer 39

for solid to gas | heat needed to vaporise 1 mole of substance from solid phase

Question 40

vaporisation

Answer 40

liquid to gas

Question 41

condensation

Answer 41

gas to liquid

Question 42

fusion

Answer 42

freezing

Question 43

Sublimation

Answer 43

solid to gas

Question 44

Deposition

Answer 44

gas to solid

Question 45

Enthalpy of phase change

Answer 45

reverse processes have same magnitude but opposite signs

Question 46

Supercritical Fluids

Answer 46

form upon compression of gases at high temp or heating liquid to very high temp at high pressure

Question 47

Supercritical fluid properties

Answer 47

of both gas and liquid

Question 48

Critical point

Answer 48

density of gas and liquid phase are equal and no phase boundary critical temp and pressure

Question 49

Phase diagrams

Answer 49

summarise phase behaviour of a substance

Question 50

Boundary lines

Answer 50

between phases that separates regions where each phase is stable

Question 51

triple point

Answer 51

where boundary lines meet at single point

Question 52

x ray diffraction

Answer 52

determines the arrangement of atoms in crystalline structure

Question 53

incoming x rays

Answer 53

atoms emit outgoing x rays

Question 54

in phase and outer phase - direction

Answer 54

in different directions

Question 55

constructive interference

Answer 55

cause diffracted beams in exposed crystals

Question 56

bragg equation

Answer 56

relates wavelength of x rays to the direction and distance between the atom planes n(wavelength) = 2dhklsin0 where dhkl = distance between planes

Question 57

amorphous

Answer 57

when solids form rapidly and molecules are locked into irregular positions

Question 58

amorphous solids

Answer 58

dont diffract xrays

Question 59

defects in solids

Answer 59

alters properities of solid material

Question 60

ceramics

Answer 60

very hard and high melting point dont conduct electricity contain metals with high oxidation stat and non metals with high negative oxidation state

Question 61

hexagonal arrangment of spheres in solids

Answer 61

most dense packing

Question 62

second layer of solids

Answer 62

sit in the dimples of first layer

Question 63

third layer of solids

Answer 63

can be in same positions as first layer or in new positions

Question 64

hexagonal closed packing

Answer 64

when 3rd layer is a repeat of first layer

Question 65

cubic closed packing

Answer 65

when third layer is different to first 2 layers

Question 66

crsytal shape

Answer 66

lattice | pattern of point

Question 67

primitive cubic lattice

Answer 67

layers of atoms stacked directly above another so that all atoms lie along straight lines at right angles

Question 68

body centred cubic lattice

Answer 68

simple cube with one entire atom in the center of cube

Question 69

face centred cubic lattice

Answer 69

simple cube with atom in centre of each face of cube

Question 70

ionic crystals

Answer 70

ions of opposite charge alternate with one another to maximis attraction and minimise repulsion

Question 71

ionic solids - packing principle

Answer 71

closed packed structures formed by larger ions | smaller ions dill interstitial spaces