unit 4 Flashcards
1
Q
gases
A
low density
indefinite shape
indefinite volume
weak IMF
2
Q
liquids
A
high density
indefinite shape
definite volume
moderate IMF
3
Q
solid
A
high density
definite shape
definite volume
strong IMF
4
Q
kinetic molecular theory
A
explains the states of matter, and is based on the idea that matter is composed of tiny particles that are always in motion
5
Q
stronger attractive forces between particles =
A
more they resist moving
6
Q
solids melt when
A
heated
7
Q
gases can be condensed by
A
decreasing temp
increasing pressure
8
Q
attractive forces and boiling/melting point relation
A
stronger attractive forces = higher melting/boiling point
9
Q
charge and attraction relation
A
larger charge = stronger attraction
10
Q
distance and attraction relation
A
longer distance = weaker attraction
11
Q
boiling point and IMF relation
A
higher boiling point = stronger IMF
12
Q
unequal electron distribution gives
A
temporary polarity
13
Q
permanent dipole adds to the
A
attractive forces between molecules
raises boiling and melting point
14
Q
polar substances dissolve in
A
polar substances
15
Q
non polar substances dissolve in
A
non polar substances
16
Q
strongest type of IMF
A
hydrogen
17
Q
ion-dipole attraction
A
ions are attracted to the dipole of polar molecules
strength determines solubility of ionic compounds in water
18
Q
London dispersion forces are present in
A
all molecules
19
Q
dipole-dipole forces are present in
A
polar molecules
20
Q
Hydrogen bonding forces are present in
A
molecules with H bonded to F, O, or N
21
Q
ion dipole forces are present in
A
mixtures of ionic compounds and polar compounds
22
Q
surface tension
A
Property of liquids that results from the tendency of liquids to minimize their surface area
23
Q
are molecules more or less stable than molecules in the interior
A
less
24
Q
IMF and surface tension relation
A
stronger IMF = higher surface tension
25
temperature and surface tension relation
increasing temp = less suface tension
26
viscosity
resistance of a liquid to flow
27
IMF and viscosity relation
larger IMF = larger viscosity
28
IMF and viscosity relation
stronger IMF = higher viscosity
29
temp and viscosity relation
increasing temp = less viscosity
30
capillary action
ability of a liquid to flow up a thin tube against the influence of gravity
31
capillary action forces
cohesive: hold liquid molecules together
adhesive: attracts outer liquid molecules to the tube's surface
32
when does capillary action stop?
until gravity counteracts the capillary action forces
33
What factors cause transitions between the solid and liquid state?
-temperature
-pressure
-heating/cooling
34
What factors cause transitions between the gas and liquid state?
-temperature
-pressure
-heating/cooling
35
Describe the relationship between the state of a substance, its temperature, and the strength of its intermolecular forces
solid: as temp increases, they become liquids. strongest IMF.
liquid: as temp increases, they become gases. strong IMF.
gas: lowest IMF
36
From what kinds of interactions do intermolecular forces originate?
interactions between charges, partial charges and temporary charges on molecules, atoms or ions
37
Why are intermolecular forces generally much weaker than bonding forces?
Bonding forces are the result of large charges acting over small distances
IMF are the result of smaller charges acting over large distances
38
What is the dispersion force?
result of fluctuations in electron distribution within molecules or atoms
39
How is the miscibility of two liquids related to their polarity?
Polar liquids are miscible with other polar liquids, but are not miscible with nonpolar liquids.
Nonpolar liquids are miscible with other nonpolar liquids
40
what does viscosity depend on?
-temp
-molecular shape
-molar mass
41
avg. kinetic energy and temperature proportion
direct
42
surface area and evaporation proportion
direct
43
vapor
gas form of a liquid
44
temp and evaporation proportion
direct
45
opposite of vaporization
condensation
46
attractive forces and evaporation relation
weaker attractive forces = faster rate of evaporation
47
volatile
vaporizes easily
48
nonvolatile
doesn't evaporate easily
49
is vaporization endothermic or exothermic?
endothermic
50
endothermic
requires energy
51
exothermic
releases energy
52
is condensation endothermic or exothermic?
exothermic
53
heat of vaporization (Dh(vap))
amount of heat energy required to vaporize one mole of the liquid
54
DH condensation =
DH vaporization
55
DH vap is always
positive
56
dynamic equillibrium
rate of vaporization = rate of condensation
57
vapor pressure
pressure exerted by the vapor when it is in dynamic equilibrium with its liquid
58
attractive forces and vapor pressure proportion
direct
59
vapor pressure and volatility proportion
direct
60
temp and vapor pressure proportion
direct
61
boiling point
temp where vapor pressure = external pressure
62
boiling
vapor bubbles form in the interior of a liquid
63
normal boiling point
temp where vapor pressure = 1 atm
64
external pressure and boiling point proportion
direct
65
what happens in the process of vaporization?
Molecules with highest kinetic energy will break free from the surface and enter the gas phase
66
what happens in condensation?
Some of the water molecules in the gas phase have less energy than the average and may reenter the liquid phase
67
Heat of vaporization (∆Hvap)
amount of heat needed to vaporize 1 mole of a liquid to a gas
68
why is ∆Hvap useful?
-calculate the amount of energy needed to vaporize a given mass of -compare volatilities of two substances
69
Which evaporates more quickly; 55 mL of water in a beaker with a diameter of 4.5 cm or 55 mL of water in a dish with a diameter of 12 cm? Is the vapor pressure of the water different in the two containers?
The beaker with a diameter of 12 cm as there is more surface area
70
How is dynamic equilibrium related to vapor pressure?
Vapor pressure is the pressure of a gas in dynamic equilibrium with the liquid
71
What happens to a system in dynamic equilibrium when it is disturbed in some way
The system responds in a way that reestablishes dynamic equilibrium
72
fusion
phase transition from solid to liquid
73
is fusion endothermic or exothermic?
endothermic
74
Heat of fusion (∆Hfus)
amount of energy needed to melt 1 mol of a solid
75
why is Heat of fusion (∆Hfus) important?
can be used to calculate the amount of heat energy needed to melt or freeze a given mass of a substance
76
solid structure type
rigid crystal structures
77
solid structures are defined by:
-their attractive forces
-arrangement of atoms
78
metal crystals structure
rigid structure of metal nuclei and inner electrons
Valence electrons are mobile and act to bond metal atoms with varying degrees of force
79
melting points of metallic crystals depend on
attractive forces
80
substitutional alloy
Metal atoms are of similar size
One type of metal atom replaces another in the metallic crystal.
One metal substitutes a similar set of attractive forces with the other metal.
Properties of the alloy are between the properties of the two metals.
81
interstitial alloy
One of the atoms is very small compared with the other.
The small atom fills spaces between the larger atoms.
Little change in volume so the added mass increases the density.
Added attractions-alloy is stronger and harder than original metals.
82
ionic crystals
ionic compounds that are solids with rigid crystalline structures (crystal lattices)
83
what is used to break ionic crystals?
large amount of lattice energy
84
how do ionic crystals break?
a disruption causes cations to line up with anions, like charges repel each other
85
molecular crystals and properties
held together by IMF, composed of nonmetal atoms or covalent molecules
soft
low boiling points
86
network crystal
lattice structure
atoms covalently bonded
one large molecule
continuous network of covalent bonds
high melting and boiling points
87
amorphous
do not form crystals
no defined melting point
88
Explain why some metals, such as Hg have melting points that are below room temperature
Hg has weaker interatomic forces than other metals and it is easier to disrupt the metallic crystal structure.
89
malleability
ability of a metal to be molded or shaped without breaking
90
ductility
Ability of a metal to be drawn into a wire
91
lattice energy
amount of energy needed to separate the ions in the crystal lattice of an ionic compound
92
mole/Avogadros number
6.02 x 10^23
93
representative particle
atom, ion, molecule, formula units
94
molar mass
one mole of a substance
95
formula mass
equal to Molar mass (amu)
