ACS Physical Chemistry Thermochemistry Study Guide

17. The criteria of spontaneity may be written as:

(a) dS U,V ≥ 0 and dU S,V ≤ 0, or (b) dA_T,V ≤ 0 and d G T,p ≤ 0.

Boyle's Law

, Pproportional to 1 / V

What is the equation for the specific heat capacity and give its units?

, q = Cs x m x delta T , Units: J K-1 g-1 , The specific heat capacity of liquid water is 4.18 JK-1 g-1 Calculate the energy required to heat 1 mol of water from 25 °C to 90 °C , q = Cs x n x ∆T = 4.18 x 18 x (90-25) = 4.9kJmol-1

Reaction Quotient Q) vs. Equilibrium Constant K)

--- at equilibrium d G=0 ; Q p= K p --- If Q p < P: d G <0 so reaction is moving L to R --- If Q p > P: d G >0 so reaction is moving R to L

What is the standard free energy of formation for an element in its standard state? delta G f

0

The Kinetic Model of Gases is based on what assumptions?

1) Gas consists of molecules in ceaseless random motion moving in straight linesbetween collisions , 2) The size of the molecule is negligible , 3) The molecules do not interact with each other or the wall of the vessel

How to calculate the delta S standard aka standard entropy change of the formation of one mole of gas from its elements?

1. Write the balanced chemical equation with the proper coefficients that make the product ONE MOLE. 2. Find the value of the one mole of product in Appendix B. This is the delta S(standard) for the product. 3. Find the value of the reactants in Appendix B for delta S(standard) and multiply them by the coefficients you got in step 1. 4. Use total = products-reactants for your final value.

Gibbs Energy G)

= H - T S = A + P V ---will decrease as a result of any spontaneous process until the system reaches equilibrium

Helmoltz Energy A)

= U - TS ---will decrease during any spontaneous process that occur at constant T and V and will achieve its minimum value at equilibrium

What is the equation for absorbance?

A = - log T

16. The Helmholtz energy is

A = U − TS.

What is Beer-Lambert Law? Give units

A = εcl , A has no units so the units must cancel out , ε usually in dm3 mol-1 cm-1 , c has to be in mol dm-3 , l has to be in cm

Polar Covalent Bond

A covalent bond in which electrons are not shared equally

What is an Electrolytic Cell?

A non-spontaneous reaction is forced by an external source of current

What is a Galvanic Cell?

An electrochemical cell that produces electricity as a result of a spontaneous reaction

Anion

An ion with a negative charge

Cation

An ion with a positive charge

What is the second law of thermodynamics?

As a whole, the universe always tends towards increasing entropy.

What is the relationship between mass and entropy delta S?

As mass increases, entropy increases

What is the relationship between molecular complexity and entropy delta S?

As molecular complexity increases, entropy increases

Boyle's Law

At constant T and for a given sample of gas, the pressure of a gas is inversely proportional to its volume

13. In real gases, molecular interactions affect the equation of state; the true equation of state is expressed in terms of virial coefficients

B, C, . . . : p Vm = RT 1 + B / V_m + C / V^2_m + · · · ).

Why can the maximum work of a system never obtained from a real process?

Because such an irreversible process will always involve some free energy being converted to heat

Why are most exothermic reactions spontaneous?

Because the large negative delta H and large energy release makes the free energy change negative.

What does more microstates mean?

Big delta S or more entropy

What type of property is internal energy?

Both extensive and a state function

What does reversing a reaction do to the standard free energy of formation? Delta G standard

Changes its sign

V propportional to T

Charles' Law

Isobaric

Constant P

Isothermal

Constant T

Isochoric

Constant V

Colloids

Contains some particles that are intermediate in size between the small particles in a solution and the larger particles in a suspension

26. The Debye-Hückel theory of activity coefficients of electrolyte solutions is based on the assumption that

Coulombic interactions between ions are dominant; a key idea of the theory is that of an ionic atmosphere.

Equation for Cp for monoatomic gas

Cp = 5/2 R

Equation for Cp for diatomic gas

Cp = 7/2 R

14. The heat capacity at constant pressure is

Cp = dH / dT p.

14. For a perfect gas, the heat capacities are related by

Cp − Cv = nR.

Equation for Cv for monoatomic gas

Cv = 3 / 2 R

Equation for Cv for diatomic gas

Cv = 5/2 R

13. The heat capacity at constant volume is defined as

Cv = dU / dT v.

22. To calculate the standard emf, form the difference of electrode potentials:

E = E right) − E left).

19. The Nernst equation is the equation for the emf of a cell in terms of the composition:

E = E − RT / νF ln Q.

What is the energy per photon and what is its units?

E = hv = hc/ lambda, Units: Joules

What happens to entropy when a substance is dissolved in another?

Entropy increases

18. The standard emf is the standard reaction Gibbs energy expressed as a potential:

E® = delta _rG® / νF.

Gibbs Phase Rule

F = C - P + 2 ---Phase P): numer of phases P=1 is for within a region, P=2 is for on the coexistence curve, P=3 is for at the critical point) ---Component C): chemically independent variable describing how many components are in the system ---Degrees of Freedom F): number of intensive variables we can change yet still be in the same phase

Bose-Einstein Condensate

Fifth state of matter that exists at extremely low temperatures and atoms behave as a single particle

Repulsive

Force exist between the molecules of gasses when Z>1

16. The Gibbs energy is

G = H − TS.

2. The total Gibbs energy of a mixture is

G = n_Aμ_A + n_Bμ_B.

29. For a condensed phase, the Gibbs energy varies with pressure as

G p_f = G p_i + V_m delta p. For a perfect gas, G p_f = G p_i + n R T ln p_f / p_i

What is a Fuel Cell?

Galvanic cells in which the reagents are supplied continuously

Clausius-Clapeyron equation

Gives the relationship between pressure and temperature for a two phase, one component system assuming that the vapor phase is ideal and the molar volume of the condensed phase is negligible compared to vapor phase

Clapeyron equation

Governs the temperature dependence of pressure in a two-phase, one component system

Enthalpy

H = U + PV

14. The enthalpy is defined as

H = U + p V

What is the relationship between atomic weight and entropy?

Heavier = increased entropy. direct

What is the cell notation for a calomel electrode?

Hg(l) | Hg2Cl2(s) | Cl-(aq)

What is internal energy, give its symbol and give the equation for a change in internal energy

Internal energy is the total energy of a system, It has the symbol U, ∆U = q + w

What happens to K as delta G becomes more negative?

It gets bigger

What happens to K as delta G becomes more positive?

It gets smaller

What happens to entropy delta S when temperature increases?

It increases

7. Thermodynamic equilibrium constant is an equilibrium constant K expressed in terms of activities (or fugacities):

K = Πa_J ν_J Equilibrium .

What is the difference between K and Q?

K is the thermodynamic equilibrium constant and is calculated at equilibrium whereas Q although calculated in the same way it doesn't have to be at equilibrium

Law of Corresponding States

Law which states "all gases have the same properties of they are compared at corresponding conditions"

During cell notation where is the oxidation half reaction?

Left

What side does the anode appear in the cell notation?

Left

Calorimetry

Method of determining heat change in a system by measuring heat exchanged in the surroundings

What happens to entropy when volume is increased?

Microstates increase, entropy increases

What does a big W mean?

More microstates

What is the relationship between number of microstates and entropy?

More microstates = higher entropy

What enthalpy sign do exothermic reactions have?

Negative

What is the likely sign of delta H and delta S for a combustion reaction?

Negative delta H, positive delta S

Can a change be spontaneous in both directions?

No

Adiabadic

No heat flows in or out of the system Q =0; delta U = W

What does delta G > 0 mean?

Non-spontaneous process - requires work

What is the relationship between work and non-spontaneous processes?

Non-spontaneous processes require work

What happens when delta H is positive and delta S is negative?

Nonspontaneous at all temperatures

What enthalpy sign do endothermic reactions have?

Positive

How to predict delta S system? change in entropy of a system

Positive delta S system means available microstates increases/disorder increases

What relationship between Q and K has a tendency to form products?

Q < K

What relationship between Q and K has a tendency to form reactants?

Q > K

11. Increased temperature favors the ____ in exothermic reactions and the _____ in endothermic reactions.

Reactants and Products.

What happens when delta H and delta S are both negative?

Reaction becomes spontaneous as temperature decreases

What happens when delta H and delta S are both positive?

Reaction becomes spontaneous as temperature increases

What direction does a reaction proceed if ln Q / K is positive?

Reaction proceeds to the left / reactants

What direction does a reaction proceed if ln Q / K is negative?

Reaction proceeds to the right/products

Pressure

Result of force distributed over an area

During cell notation where is the reduction half reaction?

Right

What side does the cathode appear in the cell notation?

Right

21. The standard potential of a couple (E®) is the standard emf of a cell in which a couple forms the ______ and the standard hydrogen electrode is the _____.

Right-hand electrode and Left-hand electrode.

4. The statistical definition of entropy is given by the Boltzmann formula

S = k ln W.

10. The variation of entropy with temperature is given by

S Tf = S Ti + Integral T_f to T_i C_p / T) dT.

15. The standard molar entropies of ions in solution are reported on a scale in which

S* H+, aq = 0 at all temperatures.

How do you find where a reaction becomes spontaneous?

Set delta G equal to zero and solve -- use T=delta H/delta S to find the temperature value.

What does fewer microstates mean?

Smaller delta S - less entropy

Is a chemical reaction proceeding to equilibrium a spontaneous or non-spontaneous change?

Spontaneous

What happens when enthalpy delta H is negative and entropy delta S is positive?

Spontaneous at all temperatures, negative free energy

What does delta G < 0 mean?

Spontaneous process - produces work

What is the relationship between work and spontaneous processes?

Spontaneous processes produce work

Le Châtelier's Principle

States that if an equilibrium system is subject to change, the equilibrium shifts in the direction which tends to counter that change

9. The Celsius and thermodynamic temperature scales are related by

T / K = θ / °C + 273.15.

If a sample absorbs 20% of light what is T and A?

T = 0.8 , A= - log 0.8 = 0.1

What is the equation for transmittance?

T = It/I0 , light intensity emmitted / light intensity added

15. During a reversible adiabatic change, the temperature of a perfect gas varies according to

T f = T i V i / V f) to the 1/ c), c = CV/R. The pressure and volume are related by p V^γ = constant, with γ = Cp,m / CV,m.

What is the relationship between temperature and entropy?

Temperature increases, entropy increases. direct

Alkaline Earth Metals

The elements in group 2A; differences shown by reactivity to water

Halogens

The elements in group 7A; highly reactive nonmetals

Noble Gases

The elements in group 8A; colorless odorless and extremely unreactive

Heat of Fushion

The energy a substance must absorb in order to change from a solid to liquid

What is the third law of thermodynamics?

The entropy of a perfect crystal is zero.

13. Third Law of thermodynamics:

The entropy of all perfect crystalline substances is zero at T = 0.

2. The Second Law in terms of entropy:

The entropy of an isolated system increases in the course of a spontaneous change: delta S total > 0.

What does change in G measure?

The extent of the spontaneity of a process, and the useful energy available from it

What does standard free energy of formation mean? Delta G standard

The free energy change that occurs when 1 mole of a compound is made from its elements

What happens when delta H and delta S have opposite signs?

The reaction occurs spontaneously at all temperatures or at none.

Endothermic

The system absorbs energy from its surroundings

Exothermic

The system releases energy to its surroundings

Charles's Law

The volume of a gas is directly proportional to its temperature in kelvins if the pressure and the # of particles of the gas are constant

Boyle's Law

The volume of a gas is inversely proportional to its pressure if the temperature and the # of particles are constant

Charles' Law

The volume of a given sample of gas at constant pressure is proportional to its absolute temperature

Which direction does the reaction proceed if delta G is positive?

To the left / to reactants

Which direction does the reaction proceed if delta G is negative?

To the right/ to products

At low vapour pressure, it is easy for a liquid to transition into a gas, true or false?

True

1. The total volume of a mixture is

V = n_AV_A + n_BV_B.

What is an extensive property?

Value depends on the amount of substance

Work Equation

W = -P ext Vf - Vi

Deposition

When a gas changes directly to a solid

Sublimation

When a solid changes directly to a gas

What is the relationship between moles of gas and entropy?

When moles of gas increase, entropy increases. direct

When a gas expands and moves a piston, how do you calculate the work done ?

Work done = external pressure times change in volume, The system is losing energy the external pressure is negative

What does negative w mean?

Work is being produced - spontaneous

What does a positive sign for w mean?

Work is required - non-spontaneous

What is a Daniell cell's cell diagram?

Zn(s) | Zn2+(aq) || Cu2+(aq) | Cu(s)

21. The activity is defined as

a A = p A / p A *.

Azeotrope

a mixture for which there is no change in composition upon boiling not possible to achieve separation)

van der Waals constants

a reflects how strong the molecules attract each other IM forces; b reflects the size of the molecule --- van der Waals equation extends beyond the ideal gas law to take into account attractive and repulsive forces

6. An endothermic process

absorbs energy as heat from the surroundings.

14. Reduction is the

addition of electrons to a species

12. The Nernst heat theorem states that the entropy change accompanying any physical or chemical transformation

approaches zero as the temperature approaches zero: delta S→0 as T→0 provided all the substances involved are perfectly ordered.

17. The van der Waals equation of state is an

approximation to the true equation of state in which attractions are represented by a parameter a and repulsions are represented by a parameter b: p = n R T / V − nb) − a n / V)^2.

11. The entropy of a substance is measured from the

area under a graph of C_p / T against T, using the Debye extrapolation at low temperatures, C_p = a T 3 as T goes to 0.

11. An azeotrope is a mixture that

boils without change of composition.

Root-mean-square r.m.s) speed

c=√3RT/M), Molar mass must be in kg mol-1, Temperature must be in K, Units = ms-1

10. A reversible change is a change that

can be reversed by an infinitesimal modification of a variable.

3. A closed system has a boundary through which matter

cannot be transferred.

16. The standard enthalpy change is the

change in enthalpy for a process in which the initial and final substances are in their standard states. The standard state is the pure substance at 1 bar.

1. The partial molar volume is the

change in volume per mole of A added to a large volume of the mixture: V_J = dV / dn J)_p,T,n′.

11. The melting temperature or freezing temperature) is the temperature at which, under a specified pressure, the liquid and solid phases of a substance

coexist in equilibrium.

10. A temperature-composition diagram is a phase diagram in which the boundaries show the

composition of the phases that are in equilibrium at various temperatures.

8. An isopleth is a line of

constant composition in a phase diagram. A tie line is a line joining two points representing phases in equilibrium.

26. The Joule-Thomson effect is the

cooling of a gas by isenthalpic expansion.

28. The temperature dependence of the Gibbs energy is given by the Gibbs-Helmholtz equation,

d G / T / dT) _p = −H / T2.

3. The thermodynamic definition of entropy is

d S = d q rev / T.

7. The Clausius inequality is

d S ≥ d q / T.

12. The temperature dependence of the equilibrium constant is given by the van 't Hoff equation:

d ln K/ dT) = delta rH* / RT^2. To calculate K at one temperature in terms of its value at another temperature, and provided delta rH* is independent of temperature, we use ln K2 − ln K1 = −delta rH*/R times 1 / T_2 − 1/ T_1).

18. The temperature dependence of the vapour pressure of a condensed phase is given by the Clausius-Clapeyron equation,

d ln p/ dT = delta vap H / RT^2.

15. The chemical potential varies with temperature as

d mu / d T _p = −S_m and with pressure as d mu / d p) _T = V_m.

5. Work is the transfer of energy by motion against an opposing force,

d w = − F d z . Heat is the transfer of energy as a result of a temperature difference between the system and the surroundings.

9. Expansion work is the work of expansion (or compression) of a system,

d w = −p ex d V. The work of free expansion is w = 0.

18. The criterion of equilibrium at constant temperature and volume,

dA T,V = 0.

23. The temperature coefficient of cell potential is given by

dE / dT = delta rS / ν F.

27. The variation of Gibbs energy with pressure and temperature are, respectively,

dG / dp) _T = V and dG / dT) _p = −S.

27. The Gibbs energy is best described as a function of pressure and temperature,

dG = V d p − S d T.

3. The fundamental equation of chemical thermodynamics relates the change in Gibbs energy to changes in pressure, temperature, and composition:

dG = Vdp − SdT + μ_Adn_A + μ_Bdn_B + · · ·.

18. The criterion of equilibrium at constant temperature and pressure,

dG T,p = 0.

9. Changes in pressure do not affect the equilibrium constant:

dK / dp) _T = 0. However, partial pressures and concentrations can change in response to a change in pressure.

24. The fundamental equation is

dU = T d S − p d V.

What is the relationship between delta G and Q?

delta G = R T ln Q

What is the equation that relates delta G to K?

delta G = negative RT ln K

What is the relationship between free energy, enthalpy, and entropy?

delta G system = delta H system - T delta S system

How to determine reaction direction from delta G?

delta G<0 reaction proceeds to the right delta G>0 reaction proceeds to the left

How to calculate delta G free energy using enthalpy delta H and entropy delta S values?

delta G=delta H-T delta S

Change in enthalpy at constant presssure

delta H = delta U + P delta V

What is the relationship between delta S of a system, q, and T?

delta S system = q rev / T

17. The depression of freezing point is given by

delta T = K f b, where K f is the cryoscopic constant.

17. The elevation of boiling point is given by

delta T = Kb b, where Kb is the ebullioscopic constant.

Relationship between heat and work

delta U = Q + W

4. The general expression for delta rG at an arbitrary stage of the reaction is

delta _rG = delta _rG* + RT ln Q.

5. The equilibrium constant K) may be written in terms of delta rG* as

delta _rG* = −RT ln K.

23. The standard Gibbs energies of formation of ions are reported on a scale in which

delta fG H+, aq) = 0 at all temperatures.

22. The standard Gibbs energy of reaction may be expressed in terms of

delta fG, delta rG =ΣProducts ν delta fG −ΣReactants ν delta fG®.

18. The enthalpy change for a process and its reverse are related by

delta forward H = −delta reverse H

12. The Gibbs energy of mixing of two liquids that form an ideal solution is given by

delta mix G = n R T x A ln x A + x B ln x B

6. The Gibbs energy of mixing of two perfect gases is given by

delta mix G = n R T x A ln x A + x B ln x B

8. The enthalpy of mixing for perfect gases is

delta mix H = 0 for perfect gases.

7. The entropy of mixing of two perfect gases is given by

delta mix S = - n R x A ln x A + x B ln x B

13. The entropy of mixing of two liquids that form an ideal solution is given by

delta mix S = n R x A ln x A + x B ln x B

20. The standard Gibbs energy of reaction is given by

delta r G = delta r H − T delta rS =ΣProducts νG m -Σreactants νG m .

23. The temperature dependence of the reaction enthalpy is given by Kirchhoff's law

delta r H T2 = delta r H T1 + Integral T2 to T1 delta r C p d

14. The standard reaction entropy is calculated from

delta r S =ΣProducts νS m -Σreactants νS m .

3. An exergonic reaction is a reaction for which

delta rG < 0; such a reaction can be used to drive another process. An endergonic reaction is a reaction for which delta rG > 0.

2. The reaction Gibbs energy is the slope of the graph of the Gibbs energy plotted against the extent of reaction:

delta rG = dG / dξ) _p,T; at equilibrium, delta rG = 0.

6. The standard reaction Gibbs energy may be calculated from standard Gibbs energies of formation,

delta rG*=ΣProducts νdelta fG* −ΣReactants νdelta fG*=Σν_Jdelta _fG* (J).

22. The standard reaction enthalpy may be estimated by combining enthalpies of formation

delta rH® = sigma Products ν delta f H − sigma Reactants ν delta f H

24. The standard reaction entropy and enthalpy are calculated from the temperature dependence of the standard emf by:

delta rS = ν F d E / dT, delta _rH = −ν FE − T d E / dT

17. Enthalpy changes are additive, as in

delta sub H = delta fus H + delta vap H

8. The entropy of transition at the transition temperature is

delta trs S = delta trs H / T trs.

16. A supercritical fluid is a

dense fluid phase above its critical temperature and pressure.

10. A supercritical fluid is a

dense fluid phase above the critical temperature.

16. A colligative property is a property that

depends only on the number of solute particles present, not their identity.

5. Thermal analysis is a technique for

detecting phase transitions that takes advantage of the effect of the enthalpy change during a first-order transition.

14. An excess function XE is the

difference between the observed thermodynamic function of mixing and the function for an ideal solution.

9. The critical temperature is the temperature at which a liquid surface

disappears and above which a liquid does not exist whatever the pressure. The critical pressure is the vapour pressure at the critical temperature.

12. Partially miscible liquids are liquids that

do not mix in all proportions at all temperatures.

4. Energy is the capacity to

do work. The internal energy is the total energy of a system.

17. The temperature dependence of the vapour pressure is given by the Clapeyron equation,

dp / dT = delta trs S / delta trs V.

5. The efficiency of a heat engine is

e = absolute value w / q h.

5. The Carnot efficiency is

e rev = 1 − T c / T h.

14. A redox reaction is a reaction in which there is a transfer of

electrons from one species to another.

14. The enthalpy change is the

energy transferred as heat at constant pressure, delta H = qp.

8. A catalyst does not affect the

equilibrium constant.

2. A transition temperature is the temperature at which the two phases are in

equilibrium.

26. A thermodynamic equation of state is an

expression for pressure in terms of thermodynamic quantities, π T = T dp / dT V − p.

Gibb's phase rule

f = c - p + 2 f is the number of degrees of freedom of a system; c is the number of components is the system; p is the number of phases present)

7. Boiling is the condition of

free vaporization throughout the liquid.

12. Calorimetry is the study of

heat transfers during physical and chemical processes.

13. The upper critical solution temperature is the

highest temperature at which phase separation occurs in a binary liquid mixture.

8. The Zeroth Law of thermodynamics states that

if A is in thermal equilibrium with B, and B is in thermal equilibrium with C, then C is also in thermal equilibrium with A.

24. An exact differential is an

infinitesimal quantity that, when integrated, gives a result that is independent of the path between the initial and final states. An inexact differential is an infinitesimal quantity that, when integrated, gives a result that depends on the path between the initial and final states.

16. The electromotive force (emf) is the cell potential when

it is balanced by an exactly opposing source of potential so that the cell reaction occurs reversibly, the composition is constant, and no current flows.

5. A phase boundary is a

line separating the regions in a phase diagram showing the values of p and T at which two phases coexist in equilibrium.

20. The equilibrium constant for a cell reaction is related to the standard emf by

ln K = νFE /RT.

The equilibrium for the dissociation of one mole of iodine vapour is 3.94 x10-4 at 900K and the standard enthalpy is 154 kJmol-. Calculate the equilibrium constant at 1200K assuming the standard enthalpy remains constant

ln K2 / K1 = - ∆rH / R 1 / T2 - 1/ T1 , ANS = 6.7 x 10-2 at 1200K

What is the Boltzmann constant?

ln number of microstates

What is the van't Hoff equation for a reaction at a given temperature

lnK = ∆rS / R - ∆rH / RT

14. A eutectic is the mixture with the

lowest melting point; a liquid with the eutectic composition freezes at a single temperature. A eutectic halt is a delay in cooling while the eutectic freezes.

9. Trouton's rule states that

many normal liquids have approximately the same standard entropy of vaporization about 85 J K−1 mol−1).

15. Incongruent melting occurs when a compound

melts into its components and does not itself form a liquid phase.

13. The chemical potential μ of a pure substance is the

molar Gibbs energy of the substance.

27. The Joule-Thomson coefficient is defined as

mu = dT / dp H.

27. The isothermal Joule-Thomson coefficient is defined as

mu T = dH / dp T = −C p mu.

9. The lever rule allows for the calculation of the relative amounts of two phases in equilibrium:

n α l α = n β l β.

3. An isolated system has a boundary through which

neither matter nor energy can be transferred.

7. Thermal equilibrium is a condition in which

no change of state occurs when two objects A and B are in contact through a diathermic boundary.

13. An electrolytic cell is an electrochemical cell in which a

non-spontaneous reaction is driven by an external source of current.

5. The chemical potential of a perfect gas is

nu = nu*+ R T ln p / p*), where nu* is the standard chemical potential, the chemical potential of the pure gas at 1 bar.

10. The chemical potential of a component of an ideal solution is given by

nu A = nu A* + R T ln x A.

22. The solvent activity is related to its chemical potential by

nu A = nu_A * + R T ln a A. The activity may be written in terms of the activity coefficient lambda A = a A / x A.

2. The system is the part of the world in which we have a special interest. The surroundings is the region

outside the system where we make our measurements.

15. The anode is the electrode at which

oxidation occurs.

6. The vapour pressure of an ideal solution is given by

p = p *_B + p *_A − p *_B x_A.

16. The vapour pressure in the presence of applied pressure is given by

p = p*e to the V_m delta P/ RT

7. The total vapour pressure of a mixture is given by

p = p_A * p*_B/{p*_A + p*_B − p*_A)y_A}.

9. An ideal solution is a solution in which all components obeys Raoult's law

p A = x A p A*) throughout the composition range.

11. An ideal-dilute solution is a solution for which the solute obeys Henry's law

p B = x B K B* and the solvent obeys Raoult's law.

12. The partial pressure of any gas is defined as

p J = x J p, where x J = n J / n is its mole fraction in a mixture and p is the total pressure.

10. A perfect gas obeys the perfect gas equation

p V = n R T, exactly under all conditions.

What is the van der Waals equation of state?

p+an /v ^2 times V-nb = RT , a and b are van der Waals parameters, specific for a given gas but independent of temperature

6. A diathermic boundary is a boundary that

permits the passage of energy as heat.

19. The Ehrenfest classification is a classification of

phase transitions based on the behavior of the chemical potential.

Isotherm

plot of P as a function of molar volume at constant temperature

11. Dalton's law states that the

pressure exerted by a mixture of gases is the sum of the partial pressures of the gases.

14. The vapour pressure is the

pressure of a vapour in equilibrium with its condensed phase.

6. The vapour pressure is the

pressure of a vapour in equilibrium with the condensed phase.

2. An equation of state interrelates

pressure, volume, temperature, and amount of substance: p = f T,V,n.

7. An adiabatic boundary is a boundary that

prevents the passage of energy as heat.

Adiabatic Process

process which no energy as heat is transferred dq = 0 ; therefore, dU=dw

13. A galvanic cell is an electrochemical cell that

produces electricity as a result of the spontaneous reaction occurring inside it.

Path Function

property that depends on the path taken to reach the state of the system

State Function

property that depends on the state of the system, and not upon the history of the system i.e. energy, entropy)

Colligative Property

property which depends only on the number of solute particles present, not on their identity i.e. vapor pressure, boiling point, freezing point, osmotic pressure)

Intensive Property

property which does not depend on the size of the system i.e. P, T, density, molar volume

Extensive Property

property which is directly proportional to the size of the system i.e. V, m, E

What is the equation for the molar heat capacity and give its units?

q = Cm x n x deltaT , Units: J K-1 mol-1

Standard electrode potentials are given as? (oxidation/reduction)

reduction

15. The cathode is the electrode at which

reduction occurs.

4. A phase diagram is a diagram showing the

regions of pressure and temperature at which its various phases are thermodynamically stable.

6. An exothermic process

releases energy as heat to the surroundings.

14. Oxidation is the

removal of electrons from a species.

10. Le Chatelier's principle states that a system at equilibrium, when subjected to a disturbance,

responds in a way that tends to minimize the effect of the disturbance.

11. Maximum work is achieved in a

reversible change.

4. A Carnot cycle is a cycle composed of a

sequence of isothermal and adiabatic reversible expansions and compressions.

4. The Gibbs-Duhem equation is

sigma n J d mu J = 0.

21. The standard Gibbs energy of formation delta fG) is the

standard reaction Gibbs energy for the formation of a compound from its elements in their reference states.

19. The standard enthalpy of combustion is the

standard reaction enthalpy for the complete oxidation of an organic compound to CO2 gas and liquid H2O if the compound contains C, H, and O, and to N2 gas if N is also present.

21. The standard enthalpy of formation delta f H is the

standard reaction enthalpy for the formation of the compound from its elements in their reference states. The reference state is the most stable state of an element at the specified temperature and 1 bar.

20. Hess's law states that the standard enthalpy of an overall reaction is the

sum of the standard enthalpies of the individual reactions into which a reaction may be divided.

Boyle Temperature

temperature at which repulsive and attractive interactions cancel and the gas appears to behave ideally

28. The inversion temperature is the

temperature at which the Joule-Thomson coefficient changes sign.

13. The lower critical solution temperature is the

temperature below which the components of a binary mixture mix in all proportions and above which they form two phases.

18. A reduced variable is

the actual variable divided by the corresponding critical constant.

7. A state function is a property that depends only on

the current state of the system and is independent of how that state has been prepared.

Heat of Combustion

the heat involved in a combustion reaction --chemical reactions that absorb heat dH > 0) are called endothermic --chemical reactions that release heat dH <0) are called exothermic

8. The First Law of thermodynamics states that

the internal energy of an isolated system is constant, delta U = q + w.

Heat q

the manner of energy transfer that results from temperature difference between system and surroundings "unorganized motion"

19. According to the principle of corresponding states, real gases at the same reduced volume and reduced temperature exert

the same reduced pressure.

12. The triple point is a point on a phase diagram at which

the three phase boundaries meet and all three phases are in mutual equilibrium.

Work w

the transfer of energy between system and surroundings as a result of existence of unbalanced forces between the two "organized motion")

Fugacity

thermodynamic property which described the deviations of ideality; the ratio f / p is the coefficient

3. A metastable phase is a

thermodynamically unstable phase that persists because the transition is kinetically hindered.

Enthalpy H)

total heat content of a system; it is equivalent to the internal energy plus the products of pressure and volume

3. An open system has a boundary through which matter can be

transferred.

8. The normal transition temperature, T trs, is the temperature at which

two phases are in equilibrium at 1 atm.

Entropy S)

unavailability of a system's thermal energy for conversion into mechanical work, often interpreted as the degree of disorder or randomness in the system ---dS=0 for cyclic processes or reversible processes in isolated system ---dS > 0 for spontaneous processes in isolated systems

14. The chemical potential is

uniform throughout a system at equilibrium.

1. A phase is a form of matter that is

uniform throughout in chemical composition and physical state.

8. The boiling temperature is the temperature at which the

vapour pressure of a liquid is equal to the external pressure.

15. The critical point is the point at which the

volumes at each end of the horizontal part of the isotherm have merged to a single point. The critical constants p_c, V_c, and T_c are the pressure, molar volume, and temperature, respectively, at the critical point.

9. The work of isothermal reversible expansion of a perfect gas is

w = − n R T ln Vf / Vi

9. The work of expansion against a constant external pressure is

w = −p ex delta V.

19. The maximum work and the Helmholtz energy are related by

w max = delta A.

19. The maximum additional non-expansion work and the Gibbs energy are related by

w_add,max = delta G.

Reversible Process

when pressure the pressure exerted on the system and the pressure of the system differ only infinitesimally so slight changes are able to be made

1. The extent of reaction ξ) is defined such that,

when the extent of reaction changes by a finite amount delta ξ, the amount of A present changes from n_A,0 to n_A,0− Δξ.

6. The composition of the vapour of an ideal solution,

y_A = x_Ap*_A/{p*_B + p*_A − p*_B)x_A}, y_B = 1 − yA.

2. The chemical potential can be defined in terms of the partial molar Gibbs energy,

μ_ J = dG / d n_J _p,T,n′.

25. The internal pressure is defined as

π T = dU / d V T . For a perfect gas, π T = 0.

What is the equation for the variation of entropy with temperature?

∆S = q rev / T , q rev = quantity of heat added reversibly ∆S = Cp ln Tf / Ti

What is the relationship between enthalpy change and internal energy?

∆U = ∆H -p∆V p is pressure (constant)

What is the relationship between ∆rG and K?

∆rG = -R T lnK

What is the relationship between electrical work and standard gibbs energy change for a reaction?

∆rG = we = -VQ, 1J = 1V x 1C

If Ecell is positive what will ∆rG be?

∆rG will be negative therefore the reaction is spontaneous

17. The cell potential and the reaction Gibbs energy are related by

− ν F E = delta rG.