L3-L5

Question 1

Natural changes occur in only one ____. All spontaneous processes are ____ and result in a ___ of usable work. However, a spontaneous process does not need to be ____.

Answer 1

direction, irreversible, loss, fast

Question 2

Nonspontaneous changes can be made to happen in the ____ direction. A spontaneous change can be reversed only by doing ____

Answer 2

unnatural, work

Question 3

For a reversible process, the entropy of universe is equal to _____. For a spontaneous process, the entropy of the universe is ___ than 0.

Answer 3

0, greater

Question 4

a measure of disorder (numbers of microscopic ways to realize a macroscopic state).

Answer 4

entropy

Question 5

A change in entropy can be calculated by the energy transferred as ___ in a ____ process divided by the ___ at which the process occurred. If the process is ____, we must devise a ____ reversible path (potentially including many steps) between the same initial and final states to calculate entropy for the process.

Answer 5

heat, reversible, temperature, irreversible, hypothetical

Question 6

The surroundings act as a perfect ___ __ with ___ heat capacity. Thus, the irreversible heat balance of the system always corresponds to a _____ heat balance of the surroundings

Answer 6

heat sink, infinite, reversible

Question 7

The entropy of an ____ ___ increases in the course of any ____ process

Answer 7

isolated system, spontaneous

Question 8

For isochoric or ____ reversible processes, an increase in ____ corresponds to an increase in the ___ __ of molecules (entropy)

Answer 8

isobaric, temperature, thermal motion

Question 9

For an isothermal reversible process, an increase in _____ or ____ with other substances results in an increase in entropy

Answer 9

volume, mixing

Question 10

For an ____ reversible process, the q = ___ and thus both the system and surroundings entropy is ___

Answer 10

adiabatic, 0, 0

Question 11

An adiabatic process that is ___ and ____ will ___ in entropy

Answer 11

isolated, irreversible, increase

Question 12

Trouton’s rule for liquids

Answer 12

Svap = 85 J/K mol

Question 13

The third law of thermodynamics shows that at ____ K, all perfect crystals in equilibrium have the same ____. It is defined as ___. At temperatures higher than zero, more different ___ ___ become available to the molecules for the same ____ state, thus the entropy will be _____ than zero.

Answer 13

0, entropy, 0, microscopic arrangements, macroscopic, greater

Question 14

Statistical thermodynamics, or ______ was proposed by Austrian Physicist Ludwig Boltzman in 1877. ____ is the number of ___ ____ available to the system for a macroscopic state of given internal energy. For a perfect crystal at 0K, there is only ___ way of arranging the molecules. The boltzman constant is related to the gas constant by _____.

Answer 14

S = kb ln (ohm), ohm, microscopic states, one, R = kNa

Question 15

Gibbs free energy can allow us to assess whether a process is ___ or not, only from properties of the ___ alone. This is under the condition that ___ and ___ are both constants during the entire process

Answer 15

spontaneous, system, pressure, temperature

Question 16

Gibbs free energy is a ___ function.

Answer 16

state

Question 17

It constant pressure and temperature, spontaneous processes are accompanied by a ___ in gibbs energy of the system. Equilibrium conditions (conditions for ____) are reached when Gibbs free energy is equal to ____

Answer 17

decrease, reversibility, 0

Question 18

the standard molar gibbs energy of formation can be calculated from its formation from its _____ in their __ __ at a given temperature and pressure. The standard molar gibbs energy of formation of an element in its most stable ___ form at 1 bar and ____ K is ____

Answer 18

elements, standard states, allotropic, 298, 0

Question 19

The temperature dependence of the gibbs energy can be calculated from the temperature dependence of the __ and ____. Very often, we assume these are ___ of the temperature

Answer 19

enthalpy, entropy, independent

Question 20

G allows us to determine the amount of ___ that can be done in a given process, as it is equal to the ___ ___ ____ the system can do during a process at constant pressure and temperature

Answer 20

work, maximum non-expansion work

Question 21

mu is the ___ __ of a substance i. It is the partial ___ ___ __ of this substance. (the molar contribution of substance i to the ____ gibbs energy of a mixture). This is a measure of the ability of substance i to bring about __ ___. A high chemical potential of a substance is an indication that this substance is __ ___

Answer 21

chemical potentially, molar gibbs energy, total, chemical change, chemical active

Question 22

A P,T-diagram shows the regions in which each phase is the most _____. At the phase boundaries, the two phases separated by the border line are in _____

Answer 22

stable, equilibrium

Question 23

where solid and liquid are in equlibrium

Answer 23

fusion curve

Question 24

where solid and gas are in equilibrium; the sublimation vapor pressure of a solid is the pressure of the vapor in equilibrium with the solid at a particular temperature

Answer 24

sublimation curve

Question 25

equilibrium between liquid and gas; the vapor pressure of a liquid is the pressure of the vapor in equilibrium with the liquid at a particular temperature.

Answer 25

vaporization curve

Question 26

The vapor pressure is function of ___ only

Answer 26

temperature

Question 27

temperature at which the liquid and solid phase coexist in equilibrium at a specified pressure.

Answer 27

melting / freezing point

Question 28

When Pex on the sample is 1 atm, the melting / freezing temperature is called the ____ melting / freezing point

Answer 28

normal

Question 29

temperature at which the vapor and liquid phase coexist in equilibrium at a specified pressured

Answer 29

boiling / condensation point

Question 30

Every point on the fusion curve indicates a ___ ___ for a different ____. Every point on the vaporization curve indicates a __ ___ for different pressures

Answer 30

melting point, pressures, condensation/boiling point

Question 31

the degrees of freedom available to a system; the numbers of independent state functions to define the system

Answer 31

F

Question 32

number of chemical components in the system

Answer 32

c

Question 33

the number of phases present in equilibrium of the system

Answer 33

P

Question 34

In one component phase-diagrams, if only a single phase is present, P = ____, then F = ___. Thus, both __ and ___ can be varied independently.

Answer 34

1, 2, temperature, pressure

Question 35

In one component phase-diagrams, if 2 phases are present simultaneously, then F = ___, so that along any phase boundary line, there is only ___ degree of freedom. If we specify that 2 phases are in equilibrium at some value of _____, P is absolutely ___ and no longer an independent or free variable of the system

Answer 35

1, 1, temperature, fixed

Question 36

the point where 3 phases are in equilibrium simultaneously

Answer 36

triple point

Question 37

the point where above a certain temperature, no matter how high the pressure is, the substance can no longer be a liquid.

Answer 37

critical point

Question 38

A substance present in the critical point is called a _______ ___. It is neither a ___ or ___, but with a density like that of a ____

Answer 38

supercritical fluid, gas, liquid, liquid

Question 39

At the critical point, the supercritical fluid exists, with the density of the liquid = to the density of the ____. The ___ between liquid and gas disappears completely, and the states become ___ and ____. The critical point signals the highest ____ are which liquid can exist.

Answer 39

gas, interface, identical indistinguishable, temperature

Question 40

Matter in the SCF condition show very different physical properties from the ___ state. SCF ____ has been used to produce decaffeinated ___< replacing the traditional hazardous ____ solvent

Answer 40

gaseous, CO2, coffee, CH2Cl2

Question 41

the clausius calpeyron equation gives a expression for ___ as a function of ___ when two phases A and B are in ____ (phase boundaries)

Answer 41

pressure, temperature, equilibrium

Question 42

If the vaporization ____ is considered to be ___ of t and p, the volume of the ___ is treated to be much more than the liquid, and the vapor is treated as an __ ___, the C-C equation is reduced to _____

Answer 42

enthalpy, independent, gas, ideal gas, V = RT/p

Question 43

Non ideal behaviour is described by replacing the concentration with the _____ _____. It depends on ___, ____, all the concentrations, and on the choice of the __ ____. In standard state, the activity coefficient equals to ___ by definition. Activity has no ___

Answer 43

activity coefficient, pressure, temperature, standard state, 1, unit

Question 44

mole fraction

Answer 44

n/total number of moles of all particles in the system

Question 45

For Q, use the actual activities during the ___ reaction process. For K, use the activities only when the reaction is in ____

Answer 45

entire, equilibrium

Question 46

For solids and liquids, activity equals ____

Answer 46

1

Question 47

if the change in gibbs free energy of the reaction is greater than 0, the ____ reaction is spontaneous, while if it is lower than 0, the _____ reaction is spontaneous

Answer 47

reverse, forward

Question 48

K can only be calculated from the ____ ___ ____ energy, which in turn can be calculated from tabulated values. K is a function of ___ only.

Answer 48

standard gibbs reaction, temperature

Question 49

The second law of thermodynamics says that in any possible process, the total entropy change of the universe can never be ____.

Answer 49

negative

Question 50

It is _____ to convert heat completely to work, because work is a process to move ___ ____ into more ordered ones.

Answer 50

impossible, random motions

Question 51

It is often extremely difficulty to apply the second law in reality,
because you have to know the entire _____ before you can decide whether a “proposed” process is ______

Answer 51

universe, spontaneous

Question 52

The second law also infers that the system receives the ____ amount of heat, and does the ____ amount of work (to the surroundings) under _____ conditions

Answer 52

maximal, maximal, reversible

Question 53

In an enthalpy driven reaction, both enthalpy and entropy are ____, and the reaction is only spontaneous at ___ temperatures.

Answer 53

negative, low

Question 54

in an entropy driven reaction, both enthalpy and entropy are ___, and the reaction is spontaneous only at ___ temperatures

Answer 54

positive, high

Question 55

Maximum work can only be realized if the process is carried out along a
_____ (infinitely ____) path. Along a reversible path, the system is near equilibrium and a small incremental change in a variable will bring the system back to its _____ state. Any real process is irreversible, thus cannot yield ______ work. In
reality, the amount of work available is always ____ than maximum for any real (irreversible) change.
Therefore, change in G reveals how much maximum energy is ____ ____ to do something humans want to perform in an ____ (useful) way, for example, through electrical work.

Answer 55

reversibly, slow, initial, maximum, less, freely available, ordered

Question 56

the ___ value of G for ___ ___ indicates that this process is ______ at standard state. However, if temperature is greater than ____ K, the polymer will automatically ___ back to monomers. Thus, it take considerable amount of energy to heat up ____ ___ to reuse the resulting monomers afterward

Answer 56

negative, polymer formation, spontaneous, 479K, recycled polymers

Question 57

If the reaction is enthalpy driven, the reaction is only spontaneous at T ___ enthalpy/entropy, while if the reaction is entropy driven, the reaction is only spontaneous at T ___ enthalpy / entropy

Answer 57

<, >

Question 58

The Vant hoff equation applies to any ___ process. The CC equation applies only to ___ and ___ processes during which ____, because the activities of solids and liquids = ____

Answer 58

general, vaporization, sublimation, K=P, 1

Question 59

Even if the change in standard gibbs free energy is greater than ____, some forward reaction must occur such as ______.

Answer 59

0, K > 0

Question 60

change in standard gibbs free energy does not dictate the ___ of a process in general, it only determines the value of ___. Only when _______, or all things are in their standard states, does this determine the spontaneity

Answer 60

spontaneity, K, Q=1

Question 61

Reaction will always occur regardless of the ____ of change in standard gibbs free energy, but the extent of the reaction, ___, is governed by change in standard gibbs free energy, and the reaction will reach equilibrium when _____

Answer 61

sign, K, K=Q