9.1-9.5

Question 1

Translational Molecules

Answer 1

Movement of the entire molecule from one place to another

Question 2

Vibrational Molecules

Answer 2

Periodic motion of atoms within a molecule

Question 3

Rotational Molecules

Answer 3

Rotation of the molecule about an axis

Question 4

Molecular Motions are AKA

Answer 4

Microstates

Question 5

More atoms means…

Answer 5

More microstates, more possible molecular motions

Question 6

Entropy

Answer 6

The driving force of diffusion
A measure of the randomness of a system: disorder

Question 7

Entropy and Temperature

Answer 7

Increasing temperature increases disorder

Question 8

Entropy and Physical States

Answer 8

Entropy increases with the freedom of motion of molecules
Gas > liquid > solid

Question 9

Entropy and Solutions

Answer 9

Mixtures generally have a higher entropy than pure liquids
Solution > pure liquid

Question 10

Entropy and Amount of Atoms

Answer 10

More complex molecules can vibrate in more ways and therefore have more entropy

Question 11

Entropy and Amount of Moles

Answer 11

The creation of more moles will increase entropy

Question 12

Entropy and Volume

Answer 12

Entropy increases when volume increases

Question 13

Entropy and Diffusion

Answer 13

Entropy increases when gas particles diffuse spontaneously

Question 14

Signs of Entropy

Answer 14

+ ~ increase in entropy
- ~ decrease in entropy

Question 15

pressure and volume

Answer 15

inversely related as P decreases V increases

Question 16

second law of thermodynamics

Answer 16

the universe is increasing in entropy (getting more disorganized)

Question 17

delta s

Answer 17

entropy of the system

Question 18

third law of thermodynamics

Answer 18

the entropy of a pure crystalline substance at absolute zero is 0
–in a perfect lattice there is only one microstate

Question 19

standard entropies increase

Answer 19

with molar mass, with number of atoms in a formula, with hotter state of matter

Question 20

spontaneous processes

Answer 20

proceed without any outside assistance

Question 21

nature spontaneously proceeds toward

Answer 21

the states the highest probabilities of existing

Question 22

processes that are spontaneous in one direction are

Answer 22

nonspontaneous in the reverse direction

Question 23

factors that affect spontaneous processes

Answer 23

pressure and temperature

Question 24

delta g unit

Answer 24

j/mol

Question 25

gibbs free energy

Answer 25

determines whether a process is spontaneous or not
- if negative the forward reaction is spontaneous
- if positive the reverse reaction is spontaneous
- if zero the system is at equilibrium

Question 26

if H<0 and S>0

Answer 26

spontaneous

Question 27

if H<0 and S<0

Answer 27

spontaneous under low temp

Question 28

if H>0 and S>0

Answer 28

spontaneous inder high temp

Question 29

if H>0 and S<0

Answer 29

not spontaneous

Question 30

phase changes

Answer 30

are at equlibrium, delta G = 0

Question 31

if something is thermodynamically favored it will

Answer 31

spontaneously occur

Question 32

kinetic control

Answer 32

the idea that sometimes spontaneous reactions may not occur
—determines if a thermodynamically favorable reaction will actually occur

Question 33

some reasons reactions with a negative delta G do not occur

Answer 33

-High activation energy
-Unfavorable orientations
–high numbers of particles that must collide simultaneously

Question 34

delta H sign meaning

Answer 34

• ~ exo
  + ~ endo

Question 35

free energy at eq

Answer 35

delta g = -RTlnK

Question 36

for more moles what does it mean which side is favored is the rxn?

Answer 36

if products have more moles it is thermodynamically favored

Question 37

Size of K and thermodynamic favorability

Answer 37

When K>1, the term lnK is positive and G is negative, thus the reaction is thermodynamically favorable.

Question 38

If K>1, G is

Answer 38

negative (lnK is positive)

Question 39

how can you overcome non-spontaneity and drive a reaction forward

Answer 39

with an external source of energy (electricity aka electrolysis)

Question 40

coupled reactions

Answer 40

combining two reactions so that the overall reaction is spontaneous
(a pos w a big neg)

Question 41

oxidation numbers rules

Answer 41

• loner = 0
• ion = charge
• o = -2, except in peroxide -1 (O2)
• hydrogen = 1 with nonmetal, -1 in metal

Question 42

electrons flow

Answer 42

from anode through wire to cathode

Question 43

anode

Answer 43

oxidation
negative

Question 44

cathode

Answer 44

reduction
positive

Question 45

1 volt

Answer 45

1 J/C

Question 46

using reduction table

Answer 46

keep larger number as reduction and switch smaller number to oxidation
-simply switch sign, NO multipliers

Question 47

cell potential

Answer 47

add voltage values

Question 48

in the salt bridge

Answer 48

cations flow to the cathode
anions flow to the cathode

Question 49

if cell potential is positive

Answer 49

the reaction is spontat=neous

Question 50

deltaG=-nFE

Answer 50

n = moles of electrons cancelled out

Question 51

deltaG=-nFE=

Answer 51

-RTlnK

Question 52

standard conditions

Answer 52

at 25C, 1atm, and with 1M

Question 53

nernst equation

Answer 53

used to calculate E value for cell under non-standard conditions
- Ecell=E-RT/nFlnQ

Question 54

concentration cell vs. voltaic cell

Answer 54

concentration - same ion for electrodes, different concentrations

Question 55

concentration cells

Answer 55

oxidation occurs at lower molarity, electrons move to solution with more positive ions

Question 56

voltaic vs electrolytic cells

Answer 56

• volatic are spontaeous
  -electrolytic are forced to occur
• voltaic seperated into two half cells
  -electrolytic one container
• volatic cell is a battery
  -electrolytic needs a battery
  -polarity of electrodes is reversed in electrolytic cells, cathode is negative anode is positive

Question 57

farday’s law
I=q/t

Answer 57

i = current in amperes A = 1C/s
q = charge in C
t = time in s
use dimensional analysis
- amount of substance at each electrode is proportional to electricity