Unit 1 (ch 6,10,11) Flashcards
1
Q
Characteristics of gas phase
A
- no defined shape or volume
- compressible
- change volume with temp
- miscible
- less dense
2
Q
Atmospheric pressure
1 ATM=
A
P ATM = force/area
1 ATM= 760 mmhg
3
Q
1 ATM = how many pascals
A
101,325
4
Q
What happens if area decreases?
A
Pressure increases
5
Q
Boyles law
A
Related to pressure and volume
P = 1/V
PV= constant
P1V1=P2V2
pressure increases, volume decreases
6
Q
Charles law
A
Related to volume and temperature
V=T
V1/T1= V2/T2
*volume increases, temperature increases
7
Q
Avogadro’s law
A
Related to volume and number of moles
V1/n1= V2/n2
*as volume increases, number of moles increases
8
Q
Amontons law
A
Related to pressure and temperature
P1/T1 = P2/T2
as pressure increases, temperature increases
9
Q
Ideal gas law
A
PV=nRT
P1V1/n1T1 = P2V2/n2T2
10
Q
Standard temp
A
0 degrees C
11
Q
Standard pressure
A
1 bar/1atm
12
Q
Standard volume
A
22.4 L/mol
13
Q
Does gas have a greater density or less density than other forms of matter?
A
less
14
Q
at STP density =
A
molar mass/molar volume
15
Q
density in relation to PV=nRT
A
PM/RT = m/v = d (M= molar mass, m = mass)
16
Q
Given that density of gases depends on their molar mass, which is the least dense?
Cl2, He, H2, N2
A
H2- least molar mass
17
Q
highest molecular weight = most or least dense?
A
most
18
Q
increase temperature, density (blank)
A
decreases
19
Q
decrease temperature, density (blank)
A
increases
20
Q
Dalton’s law of partial pressures
A
Ptot = P1 + P2 + P3…
21
Q
mole fraction
A
moles of one element/total moles of all elements
22
Q
Partial pressure of a gas =
A
mole fraction x Ptotal
23
Q
Kinetic molecular theory of gases list
A
1) gas molecules are tiny compared to the volume they occupy
2) move constantly and randomly
3) motion associated with average KE (same temp= same KE)
4) collisions with other molecules and walls of container are elastic (T and V constant)
5) assume no attraction or repulsion between gas molecules
24
Q
with gases, smaller V means (blank) collisions and (blank) pressure
A
increase, increase
25
More molecules means (blank) collisions and (blank) pressure
increase, increase
26
Higher temperature means (blank) collisions and (blank) pressure
increase, increase
27
Molecular speed and kinetic energy
KE = 1/2 mu^2
28
Three important values
- Um
- Uavg
- Urms
(most common speed)
(average speed)
(root mean square speed)
29
larger gas moves faster or slower?
slower
30
KE avg is the same for different gases at the same (blank)
temperature
31
Graham's law is related to
effusion and diffusion
32
Van der Waal's equation
(P + n^2a/v^2) x (v-nb) = nRT
33
```
solids have (blank) interparticle forces
KE (blank) attraction
```
strong,
34
```
liquids have (blank) interparticle forces
KE (blank) attraction
```
medium, >
35
```
gases have (blank) interparticle forces
KE (blank) attraction
```
weak, >>
36
strong forces = solid with (blank) boiling point
high
37
weak forces = gas with (blank) boiling point
low
38
ion-ion interactions
ionic compounds
| strongest
39
E = (blank)/(blank)
E = (Q1Q2)/d (smaller distance = stronger)
40
stronger interactions with (blank) distance
smaller
41
Interactions between polar molecules include and they relate to differences in (blank)
ELECTRONEGATIVITY
- ion-diple
- diploe-diple
- ---hydrogen
42
ion-dipole interactions
ions and polarized molecules
| ex) water and salt
43
Dipole-Dipole
weaker, less organized
44
Hydrogen
special type of dipole-dipole
O-H, N-H, or F-H
H bonded to highly electronegative element
increase boiling point
45
Dispersion forces
london dispersion, induced-dipole induced dipole
occur between all molecules
weakest
change in electron distribution
larger molecules = more force (more polarized)
46
Which is the most polarizable? I2, Br2, Cl2, F2
I2
47
Why do strenghts of London forces increase with size?
larger molecules have more electrons and therefore, more distortions and a bigger force
-nonpolar liquid (oil)= high boiling
48
Van der Waals forces
non-ideal gases
| (P + n^2a/v^2)(v-nb)=nRT
49
Thinking about the factors that influence Van der Waals constants, which do you expect to have the larges a constant? He, H2O, N2, NO
H2O
50
key point with polarity and solubility
LIKE DISSOLVES LIKE
51
O2 has (blank) solubility in H2O
limited
52
increase temp, (blank) gas solubility
decrease
53
fish example
O2 less soluble with heat, fish die in warm water
54
low pressure (high elevation) = (blank) gas solubility
lower
55
Henry's law
Cgas= KH-Pgas
| concentration, constant, partial pressure
56
hydrophobic vs hydrophillic
fearing vs loving
57
what two things influence the phase of matter?
temperature and pressure
58
solid CO2 =
dry ice
59
qualities of water
higher melting and boiling point
forms strong H-bonds
surface tension
60
cohesive forces
molecules sticking together
61
adhesive forces
molecules sticking to other things
62
stronger forces = (blank) viscous
more
63
pentane vs car oil- which is more viscous
car oil
64
What is more viscous, freshwater or seawater?
seawater
65
cold water = (blank) dense
most
66
solvent dissolves (blank)
solute
67
breaking bonds example
NaCl (ionic)
68
making bonds example
NaCl in H2O (ion-dipole)
69
delta H solution =
delta H ion-ion + delta H dipole-dipole + delta H ion-dipole
70
delta H solution = break + make
delta H ion-ion (break) + delta H hydration (make)
71
lattice energy
U = K (Q1Q2)/d
| -more negative U is harder to dissolve
72
lattice energy trend
smaller ion (top right)= larger negative energy
73
which has a higher lattice energy RbF or LiF?
LiF
74
Born-Haber cycle
series of chemical steps to make ionic solid from elements
75
delta H solution = delta H hydration (+ or -? U)
-
76
rate of vaporization depends on
pressure, temp, surface area, strength of intermolecular forces
77
temperature increases, vapor pressure (blank)
increases
78
delta H hydration for H2O is positive or negative?
negative
79
in general, if solute is nonvolatile, vapor pressure (blank)
decreases
80
nonvolatile examples
sugar and salt
81
Which of the following would not lower the vapor pressure of H2O?
- Acetic acid (118.1 C)
- Ethylene glycol (197)
- Glycerol (290)
- Methanol (64.5)
methanol
82
Raoult's law
Psolution= mole fraction solvent x P solvent
83
clausius-clapeyron equation
ln (Pvap T1/Pvap T2) = delta H vap/ R (1/T2 -1/T1)
84
vapor pressures of mixtures equation
Ptotal=mole fraction x vapor pressure + (same)
85
Colligative properties of solutions
- freezing point depression
- boiling point elevation
- density increase
- osmosis and osmotic pressure
86
molality
nsolute/kg solvent
87
boiling point elevation
delta Tb=kb x m
88
freezing point elevation
delta Tf = kf x m
89
van't hoff factor (i)
nonelectrolytes vs electrolytes
90
solvent moves from (blank) solute to (blank)
low to high
91
Osmotic pressure equation
pi= i x M (moles/L) x R x T (kelvin)
92
ethylene glycol in water is
antifreeze
93
What differentiates gases from the other phases?
no shape/volume, compressible, miscible, less dense
94
Patm=
F/A
95
What are the gas laws?
Boyles (P and V)
Charles (V and T)
Avogadros (V and n)
Amontons (P and T)
96
Ideal gas law
PV = nRT
97
standard conditions for the ideal gas law
0 degrees C and 1 atm/bar
98
1 mol ideal gas = blank L
22.4
99
gases in reactions compare (blank)
V and P
100
gas density
less dense than other faces
| d= molar mass/molar volume
101
density =
P x molar mass/ RT
102
As temperature increases, density (blank)
decreases
103
how can we use density to determine molar mass?
molar mass = dRT/P
104
Dalton's law
each gas in a mixture has a partial pressure
| Ptotal= sum of partial pressures (P1 + P2 + P3)
105
moles of gas
ntotal= n1+n2...
106
mole fraction Xx
nx/ntotal (moles of the component/ total moles)
107
Partial pressure =
mole fraction x total pressure (Px = (Xx)(Ptotal)
108
For any given mixture, the sum of the mole fractions =
1
109
Kinetic molecular theory of gases
- gas molecules tiny compared to volume they occupy
- move constantly and randomly
- motion associated with average kinetic energy
- collisions are elastic
- no attraction between molecules
110
collisions are what generates (blank)
pressure
111
smaller volume = (blank) collisions
more
112
smaller volume = (blank) pressure
increase
113
more molecules = (blank) collisions = (blank) pressure
more, increased
114
KE equation
1/2 m u^2 (m= mass, u = speed)
um= most common speed
uavg= average speed
urms= root mean squared speed
115
urms
speed of particle with KEavg
| sqrt(3RT/molar mass)
116
KEavg
1/2 m (urms)^2
117
heavier molar mass = (blank) speed
slower
118
Graham's law
gases move from high pressure to low pressure
119
rate is inversely proportional to the (blank)
square root of molar masses
| r1/r2 = sqrt (molar mass2/molar mass1)
120
Van der waal's equation
(P + n^2a/v^2)(v-nb) = nRT
121
solid- KE (blank) intermolecular attraction
122
liquid- KE (blank) intermolecular attraction
>
123
gas- KE (blank) intermolecular attraction
>>
124
strong forces and high melting = solid, liquid, or gas?
solid
125
strength of interparticle/intermolecular intereactions influences (blank)
phase, melting, and boiling points
126
weak forces and low boiling = solid, liquid, or gas
gas
127
types of interactions
```
ion-ion (E Q1Q2/d)
ion-dipole
dipole-dipole
hydrogen
dispersion forces
```
128
dispersion forces explained
nonpolar molecules form temporary or induced dipoles
129
induced dipole is the (blank)
temporary shift in the electron distribution around the atoms/bonds
130
(blank) can influence the strength of dispersion forces
shape
131
what molecules stack well and what don't?
linear, spherical
132
How can dispersion forces become strong?
added together
133
Van der Waal's forces
nonideal gases interact
134
Intermolecular forces also explain
solubility
135
If we mix H2O and MeOH, they both have what type of force? What does this mean?
dipole-dipole/hydrogen bonds
| they can form new dipole-dipole interactions with each other, increase solubility
136
If we mix H2O with octane, what forces are present? What does this mean?
dispersion, you have to break the hydrogen bonds and dispersion forces but only left with dispersion in end= unfavorable
137
Gas solubility in H2O - increased T =
decreased solubility (gases gain more KE, escape solvent)
138
Solubility in H2O depends on
gas partial pressure- Henry's law
139
What molecules form cell membranes?
molecules that interact through multiple types of forces
| - polar and non polar ends
140
cell membranes are also known as
phosopholipids
141
What do phase diagrams do?
tell us what phases should be present at a given T and P and where transitions between the phases should occur
142
supercritical region
a region where a compound behaves as sort of a gas-liquid hybrid
143
Why is water amazing?
strong hydrogen bonds
144
Solutes affect solution properties such as
melting point, boiling point, and vapor pressure
145
When we dissolve a solute in a solvent, we are doing what?
breaking some bonds and forming new ones
146
Delta H solution =
delta H hydration - U (lattice energy)
147
lattice energy =
k(Q1Q2)/d
148
Born Haber cycle
breaking a complicated chemical reaction into its basic steps and analyzing the energy for each of those steps
149
delta H hydration (NaCl) can be broken into
delta H hydration Na = delta H hydration Cl
150
Vapor pressure
the pressure exerted by a gas above a liquid in a closed system when equilibrium between evaporation and condensation is reached
151
Vapor pressure can tell us (blank) and increases with (blank)
fast; temp
152
If we dissolve a nonvolatile solute, vapor pressure
drops
153
vapor pressure of pure water is (blank) seawater
greater than
154
Raoult's law
Psolution = Xsolvent x Psolvent (mole fraction x vapor pressure of solvent)
155
mole fraction is the
ratio of moles of one component of a mixture to the entire mixture (nx/ntotal)
156
Colligative properties
depend on concentration of solute
157
Mixtures of volatile solutes can be found using what equation?
clausius-clapeyron
158
Clausius- Clapeyron
ln(PvapT1/PvapT2) = delta Hvap/R(1/T2-1/T1)
159
In a volatile mixture, Ptotal =
X1P1 + X2P2
160
Colligative properties
molality, boiling point elevation, freezing point depression, osmosis
161
molality
nsolute/kg solvent
162
boiling point elevation
delta Tb = kb x m (i)
163
freezing point depression
delta Tf = kf x m (i)
164
Van't Hoff factor is needed to account for
when dissolved, not all 1 m solutions have the same number of "particles"
165
Van't Hoff factor = i =
number of "particles" we get when we dissolve a compound
166
NaCl i =
2
167
CaCl2 i =
3
168
glucose i =
1
169
at higher concentrations of solute we see (blank)
ion pairing, vh decreases
170
Osmosis
movement of solvent through a semipermeable membrane from an area of low solute concentration to high solute concentration
171
osmotic pressure
pi = iMRT
172
Osmotic pressure is super important in
IV administration and reverse osmosis
173
Explain why the boiling point of Br2 (59C) is lower than that of iodine monochloride, ICl (97C), even though they have nearly the same molar mass.
ICl is polar while Br2 is no polar.
174
Polar liquids have higher or lower boiling point?
Higher, dipole dipole
175
In an aqueous solution containing Sn (II) and Sn (IV) salts, which cation would you expect to be the more strongly hydrated? Why?
Sn4+ because it is a smaller ion with a larger charge.
176
Which of the following compounds is expected to have the weakest interactions between its molecules? CO2, NO2, SO2, H2S
CO2
177
Which of the following compounds is expected to have the strongest interactions between its molecules? CO2, NO2, SO2, H2S
SO2
178
Why do the strengths of London dispersion forces generally increase with increasing molecular size?
Dispersion forces arise from dipoles caused by the electron distribution being distorted. Larger molecules have more electrons and therefore, more distractions and a bigger force.
179
What substances are insoluble in water? KBr (s), Benzene, C6H6 (l), Br2(l)
Benzene and Br2
180
Smaller ions of the same charge form compounds that are (blank) soluble than compounds from larger ions.
Less
181
Ions with higher charges form compounds that are (blank) soluble than ions of a lower charge.
Less
182
Rank the following compounds in order of increasing solubility in water.
CaO, BaO, KCl, KI
183
The most soluble compounds in water is th compound with the (blank) hydrophobic hydrocarbon chain.
Shortest
184
Solid helium cannot be converted directly into the vapor phase. Does the phase diagram of He have a triple point?
No, without a sublimation curve there can be no triple point.
185
What kind of intermolecular forces must be overcome during a the phase change in which solid CO2 sublimes?
Dispersion
186
What kind of intermolecular forces must be overcome during a the phase change in which CHCl3 boils?
Dispersion
| Dipole-dipole
187
What kind of intermolecular forces must be overcome during a the phase change in which ice melts?
Dispersion, dipole-dipole, hydrogen
188
At 1 ATM and 0 C, water is
Solid and liquid
189
A hot needle sinks when out on the surface of cold water. Will a cold needle float or sink in warm water?
The hot needle breaks the surface tension of the water, causing it to sink. A cold needle cannot break up the surface tension of the water, so it floats.
190
Does hot water have a higher or lower surface tension than cold water?
Lower
191
Explain why different liquids do not reach the same height in capillary tubes of the same diameter.
Cohesive forces stronger than adhesive forces reduce the height of the liquid in the capillary tube, whereas adhesive forces stronger than cohesive forces increase the height of the liquid.
192
The smaller the diameter of a tube, the (blank) the liquid rises up the tube by capillary action.
Higher
193
Water has higher surface tension and viscosity than
Methanol
194
What makes a substance soluble in water?
Polar and can form hydrogen bonds with water molecules.
195
Of the following compounds, LiF- NaCl- or KI, which should have the highest melting point?
LiF
196
The smallest distance between the ions and highest charges =
Higher lattice energy and melting point
197
When the vapor pressure of a liquid is equal or greater than atmospheric pressure, the liquid will (blank)
Boil
198
The higher the vapor pressure of a given liquid, the (blank) the boiling point.
Lower
199
As the size of atomic number increases, the Latrice energy and melting point (blank)
Decrease
200
Vapor pressure depends on (blank)
Temperature
201
The higher the temperature, the (blank) the vapor pressure.
Higher
202
The higher the molarity of the, the (blank) the osmotic pressure.
Higher
