Chem Final Flashcards
1
Q
Limiting reactant/reagant
A
the reactant that gets used up first and therfor limits amount of product that can be formed
2
Q
KMT-Kinetic Molar Theory
A
- Helps you understand what happens with a gass
- is a model
- Gasses consist of large #s of molecules that are in continuous random motion. Speed and direction can change
- The Combined volume of all of the moleculed of the gas is negligible relative to the total volume in which the gass is contained.
- attrative and repulsive forces between gas moleculed are negligible because they are going too fast
- The average KE of the molecule is proportioanal to the absolute tem (kelivin)
3
Q
elastic
A
no KE is lost
4
Q
KE
A
KE=1/2mvsquare
5
Q
slow molecules=____ temp
A
cooler
6
Q
fast molecules=____ temp
A
warmer
7
Q
Properties of gas-
A
expansion, fluidity, have minimal inter molecular attraction(moving too fast)
8
Q
diffusion
A
the spread of one substance throughout a space or throughout a 2nd substance
9
Q
effusion
A
the escape of gas molecules thorugh a tiny hole into an evacuated space
10
Q
Light gas travles_____ than heavy gass
A
faster
11
Q
heavy gas travels___ than light gas
A
slower
12
Q
Grahms Law
A
the rate of effusion for a gas is inversely proportioal to the square root of its molar mass (also for diffusion)
13
Q
pressure(def)
A
the amount of force applied on an area
14
Q
Atmospheric pressure
A
- the weight of air per unit of area
- 1.00 atm=760 torr
15
Q
manometer
A
used to measure the difference in pressure between atmospheric pressure and that of a gas in a vessel
16
Q
Standard pressure
A
- normal atmospheric pressure at sea level
- 1atm/760torr/101.325 KiloPasals
17
Q
Dalton’s law of partial pressure
A
-the total pressure of a mixture of a gas equals the sum of the pressures that each would exert if it were present alone
Ptotal=p1+p2+p3…..
18
Q
intermolecular force
A
between molcules(weak)
19
Q
intramolecular force
A
within a molecule
20
Q
van der waal forces
A
the sum of the attractive or repulsive forces between molecules (intermolecular forces)
21
Q
London Dispersion forces
A
- weakest
- for a sec most electrons are one one side which becomes more (-) that the other side
- causes polarity
- a near atom would become dipole b/c it would repel
- everything has london
22
Q
Polarizability
A
- the tendancy of an electron to distort
- strength of force is related to molecular weight. more weight=more force
23
Q
Larege atoms are ___ to polarize
A
easier
24
Q
A shorter dipole moment vector means a ___ polar bond
A
less
25
a longer dipole moment vector means a ___ polar bond
higher
26
molecules that have permanent dipoles are ____ to eachohter
attracted
27
the more___ a molecule the higher its boiling point
polar
28
hydrogen bonding
- extreme dipole
- A hydrogen bond is a type of attractive (dipole-dipole) interaction between an electronegative atom and a hydrogen atom bonded to another electronegative atom. This bond always involves a hydrogen atom. Hydrogen bonds can occur between molecules or within parts of a single molecule. A hydrogen bond tends to be stronger than van der Waals forces, but weaker than covalent bonds or ionic bonds.
29
what elements bond during hydrogen bonding
H to (N,O, or F directly) because they are the most electronegative elements.
30
What is the fundimental differnece between states of matter?
distance between particles.
31
Fluid
substance that can flow and take its containers shape (gas/liquid)
32
what is the most dense state of matter
solid (liquid id a close 2nd)
33
what is the most compressible state of matter
gas
34
surface tension
results from the net inward force experienced by the molecules on the surface of a liquid
35
cohesion
attraction of a substance to itself
36
adhesion
attraction of a substance to a surface
37
crystaline sold
particles are in highly ordered arrangement
| -a unit cell is the smalled arangement of atoms in a crystal that has the same symmetry as the whole crystal
38
amorphous
no particular order in the arrangement of particles (glass)
39
how many types of solids are there and what are their names?
2 different types
crystaline-ordered
amorphous-not ordered
40
ion crystal
metal-non metal
either S or P
Non-metal is usually P block or poly atomic
held together by ionic
41
covalent network
looking at one big molecule
| held together by covalent
42
metalic crystals
not covalent bonds
too strond to be van der waals
held by metalic
43
covalent molecular crystals
in a molecular solid the molecules are held together by relativily weak intermolecular forces
44
as more molecules escape the liquid, the pressure they exert _____
increases
45
THe boiling pressure of a liquid is the temp at which___________
the vapor pressure equals atmospheric pressure
46
the normal boiling point is the temp when to vapor pressure is ____
760 torr
47
Heat of fusion
energy required to change a solid at its melting point to a liquid
48
does the temperature change change during a phase change?
no
49
molar heat
energy needed change 1 mol
50
tripple point
whare all 3 states are in equalibrium
51
gasses
expand to fill their container
highly compressible
have extremely low densities at normal atmospheric pressure at sea level
52
Boyle's Law
- the volume of a fixed quantity of gas at constant temp is inversely proportional to the pressure
- P1+V1=P2=V2
53
hwo to convert kelvin to celsius
C+273.15
54
charles law
the volume of a fixed amount of gas at constant pressure is directly prportiolan to is absolute tem
V1/T1=V2/T2
55
Gay Lussac's Law
the pressure of a fixed amount of gas at constant volume varies directly with temp
P1/T1=P2/T2
56
Avogadro's Law
the volume of gas at constant temp and pressure is directly proportional to the # of moles of the gas
57
one mol of gas will occupy ____ volume as any other gas at the same temp and pressure
same
58
STP
standard temp and pressure
| 0 degrees celcius adn 1 atm
59
at STP one mol of gas occupies _____
22.4 L
60
IDeal gas law
PV=nRT
61
mixture
2 or more things put together
62
solution
2 or more things mixed together that you cant see the different things(homogeneous)
63
suspensions
a mix that contains particles large enough to be settled out by gravity
64
colloids
a mix where the particles are much larger than individual molecules, but still too small to settle out by gravity
65
how big are colloid particles typically?
1000 nm in diameter
66
tyndall effect
colloids ccan scatter light- how to tell a solution from a colloid
67
thixotropic mixture
kind of a solid/ kind of a liquid
| ex: toothpaste
68
brownian motion
crazy erratic random motion of colloid particle
69
what causes brownian motion
the collisons of the colloid particles with the dispersing medium
70
Solvant
have the most of in a solution
71
solute
have the least of in a solution
72
immiscible
liquids that are no soluble
73
miscible
liquids that dissolve freely in one another in any proportion
74
soluble
a substance that disolves in a solvant
75
saturated
a solvant is holding as much as possible at that temp
76
unsaturated
less than saturated/ can hold more
77
super-saturated
holds more than is possible(unstable)
78
% by mass
(mass of solute/mass of solution)(100)
79
% by volume
(volume of solute/volume of solution)(100)
80
Molarity
M=mol of solute/L of Solute
M= mol of solution/ L of solution
M=mol/L
since volume is temp dependant molarity can change with temp
81
Molality
m=mol/L
| not temp dependant
82
mole fraction
(moles of solute)/(mols of solute+moles of solvent)
83
dilution
the process of adding water to a concentrated of stock solution to achieve the molarity desired for a particular solution
84
does dilution change number of mols of a solvant/solution
no
85
like dissolve like
the intermolecular forces between solute and solvant particles must be strong enough to compete with those between solute particles and those between solvent particles
86
solvate
a solution forms the, the solvent pulls solute particles apart and surrounds them
87
ion dipole is ____ than hydrogen bonding
higher
88
"hydrated"
bonded with water
89
If an ionic salt is soluble in water it is because____
the ion-diole interations are strong
90
____ is known as the universal solvent
water\
| O-H bonds
91
what three things have to happen for a solution to form
-separate solute particles (takes energy)
-seperate solvent particles (takes solvent particle)
-new interactions between solute and solvent (release energy)
the enthalpy change of the overall process depends on the change in H for each of these steps
92
the more ___ the intermoleular attractions the more likely two substances are to be soluble with each other
similar
93
what makes something soluble in water
having a lot hydrogen bonding
94
polar disolves in ____
polar
95
non polar disolves in ___
nonpolar
96
in general the solubility of gas in water increases with increasing ___
mass
97
the solubility of liquid and solid ____ change with pressure
doesnt
98
gas solubility is ____ related to pressure
directly
99
Henry's Law
S1/P1=S2/P2
where S is the solubility of gas
and P is pressure
100
Solubility rate increases with///
temp
agitation
surface area
101
one mol of a soluble molecular compound will produce ____ mol(s) of a particle in the solution
1
102
1 mol of a soluble ionic compound will produce _____ 1
| mol of solution
more than
103
Changes in colligative properties depend on _____
of particles, not type of particle
104
colligative properties
properties of solutions that depend upon the ratio of the number of solute particles to the number of solvent molecules in a solution, and not on the type of chemical species present
105
the vapor ressure of a solution is ___ than that of the pure solvant
lower
106
vapor pressure of solutions
because of solute-solvant intermolecular attraction, higher concentrations of nonvolatiles soluts make it hard for solvant to escape to the vapor phase
107
nonvolitile
Nonvolatile refers to a substance that does not readily evaporate into a gas under existing conditions.
108
boiling point elevation and freezing point depression
non volatile solute-solvent interactions also cause solutions to have higher boilng points and lower freezing points than the pure solvent
Δ T= K(m)
where Δ T is the boiling point K is a constant and m is molality
109
Δ T= K(m) (x)
| what is X
x is the number of particles that one solute particle actually produces in solution
for molecular compounds x=1
110
osmosis
diffusion of a solvent through a semipermeable membrane
111
Semi permeable membranes
are barriers that allow some particles to crossq
112
vant hoff factor
reassociation is more likely at higher concentration there fore the # of particles present is concentation dependant
113
energy
the ability to do work or transfer heat
114
work
used to cause an object to move
energy used to move an object over some distance is work
w=f(d)
115
heat
energy used to change the temp higher is heat
116
heat flows from ____ to ____
warmer objects; cooler objects
117
kinetic energy
energy an object posses by virtue of its motion
118
temperature
measure of the average kinetic energy of the particles
119
What is the SI unit of energy
Joule
120
1 calorie is....
4.18 J
121
law of conservation of energy
| first law of thermodynamics
energy can be converted from one forme to another but it can be neither created nor destroyed
122
system
part of the universe you are focusing on
123
surrounding
everything that is not the system
124
endothermic
heat goes in to your system from the surrounding
125
exothermic
release energy/heat
126
energy gained by the surrounding=
energy lost from the system
127
freezing is an ____thermic process
exo
128
heat capacity
energy required to raise the temp 1 K/1 C
129
specific heat
the amount of heat per unit mass required to raise the temperature by one degree Celsius
130
specific heat equation
q=mcΔt
131
heat lost by hot=____
heat gained my cold
132
enthalpy
the internal energy plus the product of pressure and volume of a system
133
is there a way to tell the exact amount of enthalpy of a system?
no, but we can measures changes in enthalpy
| Δ H
134
how to determine Δ H
take the enthalpy of the products minus the enthalpy of the reactants
Δ H=H products-Hreactants
135
when Δ H is (+)
a process is endothermic
136
when Δ H is (-)
a process is exothermic
137
enthalpy is extensive property
dependent on sample size
138
the Δ H for the reverse reaction is _____
equal in size but opposite size than the forward reaction
139
Δ H of a reaction depends on
the state of the products and reactants
140
1000 cal= how many kcal
1 kcal
141
1 k cal is how many kJ
4.184 kilo joules
142
thermo chemical equations
a balanced equation that includes states of matter of all reactants and products and the energy change
143
enthalpy (or heat) of combustion
the enthalpy change for the complete combustion of one mol of the substance
144
standard conditions
NOT STP
| 1 atm and 25 celcius
145
molar enthalpy of vaporization
the heat required to vaporize one mole of a liquid
146
molar enthalpy of fusion
the heat required to melt one mol of solid
147
Hess's Law
- if a reaction is carried out in a seried of steps Δ H for the overall reaction will be equal to the sum of the enthalpy changes for the individual step
- because Δ H is a state function the total enthalpy change depends only on the initial state of the reactants and the final state of the products
148
enthalpy for motion- Δ Hf
the enthalpy change for the reaction in which one mol of a compound is made from its constituent elements in their elemental forms
-for any element in its elemnetal for Δ Hf=0
measued under standard conditions
149
driving forces of reaction spontaneity
- enthalpy (the majority of cchemical reactions are exothermic. products are more stable than the reactants.
- the tendancy of nature is to proceed in a direction that leads to lower energy
150
are all spontanious reactions exothermic?
no
151
entropy
can be though of as a measure of the randomness of a system
| -related to moles of motion of molecules
152
the 2nd law of thermodynamics
the entropy of the universe is always increasing
| in any spontanious process ther is an increase in the entropy of the universe
153
the number of microstates and the entropy tends to increase with increase in....
- temp
- volume
- # of independantly moving molecules
- increases with the freedon of motion of molecules
154
what state has the highest entropy
G>L>S
155
3rd law of thermodynamics
The entropy of a perfect crystal, at absolute zero kelvin, is exactly equal to zero
156
free energy changes
ΔG=ΔH-TΔS
T is the temperature on the Kelvin scale. In introductory courses we make the assumption that DeltaHo and DeltaSo, do not change as the temperature changes.
when G is negatice the reaction is sponaneous.
ΔH is the enthalpy term
TΔS is the entropy term
157
rate deifinition
how fast a reaction takes place
158
factors effecting rate
```
collision frequency
collision efficiancy
nature(where they are in the activity series)
surface area
presence of catalyst
conentration
```
159
how is temperature related to reaction rate
is related to KE
Related to speed/velocity
the higher the temp the higher the KE
the higher the KE the easier it is to get over the energy barrier
160
how is concentration related to reaction rate
increasing the reactant concentration results in...
- more collisions
- more collisions per second(higher conentration frequency)
- Higher KE
- more collisions per second
- greater statistical chance
- more reactant molecules with enough energy to happen
- the actual affect must be measured experimentally
161
Catalyst
- do not change energy of reation
- DO change the rate
- heterogeneous=different state than reaction
- homogeneous=same state
162
Rate Law
- an equation that related reaction rate and concentrations of reactants
- only applicable for a specific reaction at a given
163
order definition
the power to which a reaction oncentration is raised
164
orders of rate law
0 order- has no effect as long as it is there
First order=directly
Second=square of coefficient of reactant
may or may not match the coefficients
165
how does the rate law constant change with temp?
increases with temp
166
order of the reaction
sum of all the orders
167
Inhibitor
- substance that slows down reactions
| - opposite of a catalyst
168
the rate (is conctant/changes) over the course of the reaction
changes
169
reactions mechanism
the step-by-step sequence of reactions by which the overall chemical change occurs.
-consists of the complete sequene
170
intermediates
species that appear in some steps but not in the net equation
171
simple/elementary reaction
occurs in one step
-the reaction rate of that step is proportional to the product of the reactant concentrations, each of which is raised to its stoichiometric coefficient
172
complex reaction
ours in 2 or more steps
- the rate law is determined from the slowest step because it has the lowest rate.
- rate determining step
173
rate determining step
slowest rate step in a reaction
174
can a reaction go backwards
yes
175
if the reaction is exothermic in forward then it is ____ in the backwards
endothermic
176
is the rate of a chemical reaction constant?
no
177
equalibrium
whent the 2 reaction rates (both forward and backwards) become equal
178
dynamic equalibrium
stoff is still goin on a equal rates
179
equalibrium constant
```
-Keq
aA+bB=cC+dD
rateforward=k[A]a[B]b
ratebackwards= k[C]c[D]d
in equilibrium ratef=rateb
so.. k[A]a[B]b= k[C]c[D]d
Or..
(Kf/Kr)=( [C]c[D]d/[A]a[B]b)=Keq
PRODUCTS OVER REACTANTS COEDDICIENTS BECOME EXPONENTS- SOLIDS AND LIQUIDS DON’T GO IN
```
180
Keq is ___ the initial concentrations
independent of
181
Keq is _____ to temp
dependant
182
Keq is found_____
experimentally
183
why are pure solids and liquids omitted from the Keq equation
their concentration cannot change
184
Keq<10 to the (-3)
mostly reactants
185
Keq>10 to the (3)
mostly products
186
Keq between 10 to the -3 and 10 to the 3rd
balanced
187
how many equalibrium positions are there for a single reaction?
many
188
equalibrium positions
a set of concentrations that result in equalibrium
189
le chateliers principle
if a system at equalibrium is distured by a change in tem. pressure, or concentration of one of the components the system will shift its equalibrium position so as to counteract the effect of the disturbance
190
equalibrium will shift ___ from the side you add to
away
191
equalirium will shift-___ the side you take from
towards
192
gas equalibrium
increase pressure=decrease container volume
derease container volume=increase concentration of gas
high pressure favors the side with the lowest volume
with more reactant gas molecules, equalibrium shifts to the right
with more product gas molecules equalibrium shifts to the left
193
solubility product constant
Ksp
-similar to Keq of a sparingly soluble salt
-the product of the molar concentrations of its ions in a saturate solution
--bassically the product of the ion concentrations
-raised to the power of their coeffs
Ksp=[A]a[B]b
194
reaction quotient
- Q
| - basically Keq but not at equilibrium. Use same equation but with concentratiosn that do not result in Keq
195
Q= Keq
at equilibrium
196
Q
Shifts to the right(consuming reactants and forming products to attain equilibrium)
197
Q>Keq
shifts to the right (consuming products and forming reactants to achieve equilibrium.
198
Qsp
Qsp
| -if you sub in initial concentrations in to Ksp equation you do not get the SOLUBILITY PRODUCT you will get Q
199
Qsp=Ksp
saturated solutions and nothing happens
200
Qsp
Unsaturated and no precipitate forms
201
Qsp>Ksp
A precipitate will form and reduce the concentrations of the ions until the products of their concentrations in Ksp expression equals the numerical value Ksp
202
Common ion effect
- Shift in equilibrium position that occurs because of
the addition of an ion already involved in the
equilibrium reaction.
An application of Le Châtelier’sprinciple.
The lowering of the solubility of a substance because of the presence of a commo ion is called the common ion effect.
203
properties of acids
- sour taste
- ractive
- burns
- turns blue litmus paper red
- ph less than 7
- reacts with active metals to produce H2
- reacts with carbonates
- conducts electric currents
204
properties of bases
- bitter
- slippery
- turns red litmus paper blue
- ph greater than 7
- conducts electric current
205
binary acids
countains only 2 elements
typically hydrogen plus one of the mroe elctronegative elemets
-ic
206
oxy acids
omosed of hydrogen, oxygen and a third element
207
acid naming
i ATE something ICky and it gave me and (ITE)(OUS)
208
arrhenius
defined an aid as any electrolite that produces H+ ions when dissolved in water
defined a base as any eletrolye that produces hydroxide
209
what do u get when you put base in acid
salt water
210
bronsted lowry
acid=anything that gives an H+
base=anything that takes a H+
water acts as a bronstead lowry base and abstracts
211
Lewis definition of base and acid
acid=e- pair acceptor
| base=e- pair donor
212
weak acid/bases
implies that little or only partial dissociation
213
strong acid/bas
implies complete dissociation
| -any soluble OH in a base is strong
214
conjugate
- means to join together
- when you add an acid and a base you get conjigate aid and base
- acid has more H+
- the species that remains after a bronstead lowry acid has given up a proton in the onjugate base of that aicd
- the species that is formed when a bronstead lowry base gains a proton is the conjugate acid of that base
215
vaporization
solid/liquid to gas
216
volitile
vaporizes easily
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