question

The entropy of a perfect crystal is zero.

answer

What is the third law of thermodynamics?

question

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

answer

What is the second law of thermodynamics?

question

More microstates = higher entropy

answer

What is the relationship between number of microstates and entropy?

question

Temperature increases, entropy increases (direct)

answer

What is the relationship between temperature and entropy?

question

Heavier = increased entropy (direct)

answer

What is the relationship between atomic weight and entropy?

question

Entropy increases

answer

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

question

When moles of gas increase, entropy increases (direct)

answer

What is the relationship between moles of gas and entropy?

question

deltaG(system)=deltaH(system)-TdeltaS(system)

answer

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

question

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

answer

What does change in G measure?

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Spontaneous processes produce work

answer

What is the relationship between work and spontaneous processes?

question

Non-spontaneous processes require work

answer

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

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Work is being produced - spontaneous

answer

What does -w mean?

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Work is required - non-spontaneous

answer

What does a positive sign for w mean?

question

No

answer

Can a change be spontaneous in both directions?

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Value depends on the amount of substance

answer

What is an extensive property?

question

Non-spontaneous process - requires work

answer

What does ?G > 0 mean?

question

Spontaneous process - produces work

answer

What does ?G < 0 mean?

question

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

answer

What does standard free energy of formation mean? ?Go

question

Changes its sign

answer

What does reversing a reaction do to the standard free energy of formation? ?G0

question

Because the large negative ?H/large energy release makes the free energy change negative.

answer

Why are most exothermic reactions spontaneous?

question

The reaction occurs spontaneously at all temperatures or at none.

answer

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

question

Spontaneous at all temperatures, negative free energy

answer

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

question

Negative ?H, positive ?S

answer

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

question

Nonspontaneous at all temperatures

answer

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

question

Reaction becomes spontaneous as temperature increases

answer

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

question

Reaction becomes spontaneous as temperature decreases

answer

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

question

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

answer

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

question

Set ?G equal to zero and solve -- use T=deltaH/deltaS to find the temperature value.

answer

How do you find where a reaction becomes spontaneous?

question

Spontaneous

answer

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

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?G0 reaction proceeds to the left

answer

How to determine reaction direction from ?G?

question

To the left / to reactants

answer

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

question

To the right/ to products

answer

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

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Positive ?S(system) means available microstates increases/disorder increases

answer

How to predict ?S(system)? (change in entropy of a system)

question

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 deltaS(standard) for the product. 3. Find the value of the reactants in Appendix B for deltaS(standard) and multiply them by the coefficients you got in step 1. 4. Use total = products-reactants for your final value.

answer

How to calculate the ?So (aka standard entropy change) of the formation of one mole of gas from its elements?

question

?G=?H-T?S

answer

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

question

?G=-RT ln K

answer

What is the equation that relates ?G to K?

question

ln(# of microstates)

answer

What is the Boltzmann constant?

question

More microstates

answer

What does a big W mean?

question

Big ?S - more entropy

answer

What does more microstates mean?

question

Smaller ?S - less entropy

answer

What does fewer microstates mean?

question

Microstates increase, entropy increases

answer

What happens to entropy when volume is increased?

question

?S(system)=qrev/T

answer

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

question

It increases

answer

What happens to entropy ?S when temperature increases?

question

As mass increases, entropy increases

answer

What is the relationship between mass and entropy ?S?

question

As molecular complexity increases, entropy increases

answer

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

question

?G=RTlnQ

answer

What is the relationship between ?G and Q?

question

It gets smaller

answer

What happens to K as ?G becomes more positive?

question

It gets bigger

answer

What happens to K as ?G becomes more negative?

question

Reaction proceeds to the left/reactants

answer

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

question

Reaction proceeds to the right/products

answer

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

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

answer

Extensive Property

question

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

answer

Intensive Property

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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

answer

van der Waals constants

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

answer

Isotherm

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

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Law of Corresponding States

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

answer

Boyle Temperature

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

answer

Heat (q)

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

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Work (w)

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

answer

State Function

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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

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Reversible Process

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

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Path Function

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

answer

Adiabatic Process

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

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Enthalpy (H)

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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

answer

Heat of Combustion

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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

answer

Entropy (S)

question

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

answer

Helmoltz Energy (A)

question

= H - TS = A + PV ---will decrease as a result of any spontaneous process until the system reaches equilibrium

answer

Gibbs Energy (G)

question

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

answer

Fugacity

question

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

answer

Gibbs Phase Rule

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

answer

Azeotrope

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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)

answer

Colligative Property

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--- at equilibrium dG=0 ; Qp=Kp --- If Qp < P: dG P: dG >0 so reaction is moving R to L

answer

Reaction Quotient (Q) vs. Equilibrium Constant (K)

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

answer

Colloids

question

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

answer

Bose-Einstein Condensate

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Result of force distributed over an area

answer

Pressure

question

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

answer

Charles's Law

question

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

answer

Boyle's Law

question

The system absorbs energy from its surroundings

answer

Endothermic

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

answer

Heat of Fushion

question

The system releases energy to its surroundings

answer

Exothermic

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When a gas changes directly to a solid

answer

Deposition

question

When a solid changes directly to a gas

answer

Sublimation

question

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

answer

Alkaline Earth Metals

question

The elements in group 7A; highly reactive nonmetals

answer

Halogens

question

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

answer

Noble Gases

question

An ion with a negative charge

answer

Anion

question

An ion with a positive charge

answer

Cation

question

A covalent bond in which electrons are not shared equally

answer

Polar Covalent Bond

question

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

answer

2. An equation of state interrelates

question

permits the passage of energy as heat.

answer

6. A diathermic boundary is a boundary that

question

prevents the passage of energy as heat.

answer

7. An adiabatic boundary is a boundary that

question

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

answer

7. Thermal equilibrium is a condition in which

question

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.

answer

8. The Zeroth Law of thermodynamics states that

question

T/K = ?/°C + 273.15.

answer

9. The Celsius and thermodynamic temperature scales are related by

question

pV = nRT, exactly under all conditions.

answer

10. A perfect gas obeys the perfect gas equation

question

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

answer

11. Dalton's law states that the

question

p_J = x_J p, where x_J = n_J/n is its mole fraction in a mixture and p is the total pressure.

answer

12. The partial pressure of any gas is defined as

question

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

answer

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

question

pressure of a vapour in equilibrium with its condensed phase.

answer

14. The vapour pressure is the

question

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.

answer

15. The critical point is the point at which the

question

dense fluid phase above its critical temperature and pressure.

answer

16. A supercritical fluid is a

question

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 = nRT/(V? nb) ? a(n/V)^2.

answer

17. The van der Waals equation of state is an

question

the actual variable divided by the corresponding critical constant.

answer

18. A reduced variable is

question

the same reduced pressure.

answer

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

question

outside the system where we make our measurements.

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

question

transferred.

answer

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

question

cannot be transferred.

answer

3. A closed system has a boundary through which matter

question

neither matter nor energy can be transferred.

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3. An isolated system has a boundary through which

question

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

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4. Energy is the capacity to

question

dw = ?Fdz . Heat is the transfer of energy as a result of a temperature difference between the system and the surroundings.

answer

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

question

releases energy as heat to the surroundings.

answer

6. An exothermic process

question

absorbs energy as heat from the surroundings.

answer

6. An endothermic process

question

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

answer

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

question

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

answer

8. The First Law of thermodynamics states that

question

dw = ?p_exdV. The work of free expansion is w = 0.

answer

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

question

w = ?p_ex?V.

answer

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

question

w = ?nRT ln(V_f /V_i).

answer

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

question

can be reversed by an infinitesimal modification of a variable.

answer

10. A reversible change is a change that

question

reversible change.

answer

11. Maximum work is achieved in a

question

heat transfers during physical and chemical processes.

answer

12. Calorimetry is the study of

question

C_V = (?U/?T) _V.

answer

13. The heat capacity at constant volume is defined as

question

C_p = (?H/?T) _p.

answer

14. The heat capacity at constant pressure is

question

C_p ? C_V = nR.

answer

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

question

H = U + pV.

answer

14. The enthalpy is defined as

question

energy transferred as heat at constant pressure, ?H = q_p.

answer

14. The enthalpy change is the

question

T_f = T_i(V_i/V_f)^(1/c), c = CV,m/R. The pressure and volume are related by pV^? = constant, with ? = C_p,m/C_V,m.

answer

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

question

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.

answer

16. The standard enthalpy change is the

question

?_subH® = ?_fusH® + ?_vapH® .

answer

17. Enthalpy changes are additive, as in

question

?forwardH® = ??reverseH®.

answer

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

question

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.

answer

19. The standard enthalpy of combustion is the

question

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

answer

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

question

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.

answer

21. The standard enthalpy of formation (?_fH® ) is the

question

?_rH® =?Products ??fH® ??Reactants ??fH® .

answer

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

question

?_rH® (T2) = ?_rH® (T1) + Integral (T2 to T1) ?_rC® pdT.

answer

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

question

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.

answer

24. An exact differential is an

question

?_T = (?U/?V) _T . For a perfect gas, ?_T = 0.

answer

25. The internal pressure is defined as

question

cooling of a gas by isenthalpic expansion.

answer

26. The Joule-Thomson effect is the

question

? = (?T/?p) _H.

answer

27. The Joule-Thomson coefficient is defined as

question

?_T = (?H/?p) _T = ?C_p?.

answer

27. The isothermal Joule-Thomson coefficient is defined as

question

temperature at which the Joule-Thomson coefficient changes sign.

answer

28. The inversion temperature is the

question

The entropy of an isolated system increases in the course of a spontaneous change: ?S_tot > 0.

answer

2. The Second Law in terms of entropy:

question

dS = dq_rev /T.

answer

3. The thermodynamic definition of entropy is

question

S = k lnW.

answer

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

question

sequence of isothermal and adiabatic reversible expansions and compressions.

answer

4. A Carnot cycle is a cycle composed of a

question

? = |w|/q_h.

answer

5. The efficiency of a heat engine is

question

?_rev = 1 ? T_c /T_h.

answer

5. The Carnot efficiency is

question

dS ? dq/T.

answer

7. The Clausius inequality is

question

two phases are in equilibrium at 1 atm.

answer

8. The normal transition temperature, T_trs, is the temperature at which

question

?_trsS = ?_trsH/T_trs.

answer

8. The entropy of transition at the transition temperature is

question

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

answer

9. Trouton's rule states that

question

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

answer

10. The variation of entropy with temperature is given by

question

area under a graph of C_p /T against T, using the Debye extrapolation at low temperatures, C_p = aT3 as T?0.

answer

11. The entropy of a substance is measured from the

question

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

answer

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

question

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

answer

13. Third Law of thermodynamics:

question

?_rS® =?Products ?S® m -?reactants ?S® m .

answer

14. The standard reaction entropy is calculated from

question

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

answer

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

question

A = U ? TS.

answer

16. The Helmholtz energy is

question

G = H ? TS.

answer

16. The Gibbs energy is

question

(a) dS_U,V ? 0 and dU_S,V ? 0, or (b) dA_T,V ? 0 and dG_T,p ? 0.

answer

17. The criteria of spontaneity may be written as:

question

dA_T,V = 0.

answer

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

question

dG_T,p = 0.

answer

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

question

w_max = ?A.

answer

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

question

w_add,max = ?G.

answer

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

question

?_rG® = ?_rH® ? T?_rS® =?Products ?G® m -?reactants ?G® m .

answer

20. The standard Gibbs energy of reaction is given by

question

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

answer

21. The standard Gibbs energy of formation (?_fG®) is the

question

?_fG®, ?_rG® =?Products ??fG® ??Reactants ??fG®.

answer

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

question

?_fG® (H+, aq) = 0 at all temperatures.

answer

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

question

dU = TdS ? pdV.

answer

24. The fundamental equation is

question

.

answer

25. The Maxwell relations are

question

expression for pressure in terms of thermodynamic quantities, ?_T = T(?p/?T) _V ? p.

answer

26. A thermodynamic equation of state is an

question

dG = Vdp ? SdT.

answer

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

question

(?G/?p) _T = V and (?G/?T) _p = ?S.

answer

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

question

(?(G/T)/?T) _p = ?H/T2.

answer

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

question

G(p_f) = G(p_i) + V_m?p. For a perfect gas, G(p_f) = G(p_i) + nRT ln(p_f/p_i).

answer

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

question

uniform throughout in chemical composition and physical state.

answer

1. A phase is a form of matter that is

question

equilibrium.

answer

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

question

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

answer

3. A metastable phase is a

question

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

answer

4. A phase diagram is a diagram showing the

question

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

answer

5. A phase boundary is a

question

pressure of a vapour in equilibrium with the condensed phase.

answer

6. The vapour pressure is the

question

free vaporization throughout the liquid.

answer

7. Boiling is the condition of

question

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

answer

8. The boiling temperature is the temperature at which the

question

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

answer

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

question

dense fluid phase above the critical temperature.

answer

10. A supercritical fluid is a

question

coexist in equilibrium.

answer

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

question

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

answer

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

question

molar Gibbs energy of the substance.

answer

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

question

uniform throughout a system at equilibrium.

answer

14. The chemical potential is

question

(?? /?T) _p = ?S_m and with pressure as (?? /?p) _T = V_m.

answer

15. The chemical potential varies with temperature as

question

p = p*e^(V_m?P/RT).

answer

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

question

dp/dT = ?_trsS/?_trsV.

answer

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

question

d ln(p/dT) = ?_vapH/RT^2.

answer

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

question

phase transitions based on the behavior of the chemical potential.

answer

19. The Ehrenfest classification is a classification of

question

change in volume per mole of A added to a large volume of the mixture: V_J = (?V/?n_J)_p,T,n?.

answer

1. The partial molar volume is the

question

V = n_AV_A + n_BV_B.

answer

1. The total volume of a mixture is

question

?_ J = (?G/?n_J) _p,T,n?.

answer

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

question

G = n_A?_A + n_B?_B.

answer

2. The total Gibbs energy of a mixture is

question

dG = Vdp ? SdT + ?_Adn_A + ?_Bdn_B + · · ·.

answer

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

question

?n_Jd?_J = 0.

answer

4. The Gibbs-Duhem equation is

question

? = ?*+ RT ln(p/p*), where ?* is the standard chemical potential, the chemical potential of the pure gas at 1 bar.

answer

5. The chemical potential of a perfect gas is

question

?_mixG = nRT(x_A ln x_A + x_B ln x_B).

answer

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

question

?_mixS = -nR(x_A ln x_A + x_B ln x_B).

answer

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

question

?_mixH = 0 for perfect gases.

answer

8. The enthalpy of mixing for perfect gases is

question

(p_A = x_Ap_A*) throughout the composition range.

answer

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

question

?_A = ?_A* + RT ln x_A.

answer

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

question

(p_B = x_BK_B*) and the solvent obeys Raoult's law.

answer

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

question

?_mixG = nRT(x_A ln x_A + xB ln xB).

answer

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

question

?_mixS = -nR(xA ln xA + xB ln xB).

answer

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

question

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

answer

14. An excess function (XE) is the

question

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

answer

16. A colligative property is a property that

question

?T = K_bb, where Kb is the ebullioscopic constant.

answer

17. The elevation of boiling point is given by

question

?T = K_fb, where Kf is the cryoscopic constant.

answer

17. The depression of freezing point is given by

question

a_A = p_A/p_A*.

answer

21. The activity is defined as

question

?_A = ?_A* + RT ln a_A. The activity may be written in terms of the activity coefficient ?_A = a_A/x_A.

answer

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

question

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

answer

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

question

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

answer

5. Thermal analysis is a technique for

question

p = p*_B + (p*_A ? p*_B)x_A.

answer

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

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

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

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

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

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

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8. An isopleth is a line of

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n?l? = n?l?.

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

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

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

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boils without change of composition.

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11. An azeotrope is a mixture that

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do not mix in all proportions at all temperatures.

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12. Partially miscible liquids are liquids that

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

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13. The upper critical solution temperature is the

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

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13. The lower critical solution temperature is the

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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.

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14. A eutectic is the mixture with the

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

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15. Incongruent melting occurs when a compound

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when the extent of reaction changes by a finite amount ??, the amount of A present changes from n_A,0 to n_A,0? ??.

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

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?_rG = (?G/??) _p,T; at equilibrium, ?_rG = 0.

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

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?_rG 0.

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3. An exergonic reaction is a reaction for which

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?_rG = ?_rG* + RT ln Q.

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

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?_rG* = ?RT ln K.

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5. The equilibrium constant (K) may be written in terms of ?_rG* as

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?rG*=?Products ??fG* ??Reactants ??fG*=??_J?_fG* (J).

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

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K = ?a_J ?_J Equilibrium .

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

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equilibrium constant.

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8. A catalyst does not affect the

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(?K/?p) _T = 0. However, partial pressures and concentrations can change in response to a change in pressure.

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

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

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

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Reactants and Products.

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

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

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

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

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13. A galvanic cell is an electrochemical cell that

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

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

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removal of electrons from a species.

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14. Oxidation is the

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addition of electrons to a species

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14. Reduction is the

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electrons from one species to another.

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

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oxidation occurs.

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15. The anode is the electrode at which

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reduction occurs.

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15. The cathode is the electrode at which

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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.

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

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??FE = ?_rG.

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

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E® = ?_rG® /?F.

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

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E = E® ? (RT/?F) ln Q.

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

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ln K = ?FE® /RT.

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

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Right-hand electrode and Left-hand electrode.

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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 _____.

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E® = E® (right) ? E® (left).

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

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dE® /dT = ?_rS® /?F.

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23. The temperature coefficient of cell potential is given by

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?_rS ® = ?FdE® /dT, ?_rH® = ??(FE ® ? TdE® /dT).

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

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

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Calorimetry

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Negative

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What enthalpy sign do exothermic reactions have?

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Positive

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What enthalpy sign do endothermic reactions have?

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

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Le Châtelier's Principle

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Constant P

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Isobaric

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Constant T

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Isothermal

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Constant V

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Isochoric

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No heat flows in or out of the system (Q =0; ?U = W)

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Adiabadic

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?U = Q + W

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Relationship between heat and work

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W = -Pext (Vf - Vi)

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Work Equation

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H = U + PV

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Enthalpy

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?H = ?U + P?V

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Change in enthalpy at constant presssure

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Cv = (3/2)R

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Equation for Cv for monoatomic gas

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Cp = (5/2)R

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Equation for Cp for monoatomic gas

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Cv = (5/2)R

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Equation for Cv for diatomic gas

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Cp = (7/2)R

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Equation for Cp for diatomic gas

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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)

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Gibb's phase rule

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

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Boyle's Law

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, P?1/V

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Boyle's Law

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

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Charles' Law

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Charles' Law

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V?T

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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

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The Kinetic Model of Gases is based on what assumptions?

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

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

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

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What is the van der Waals equation of state?

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

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

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, q = Cs x m x ?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

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

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

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

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Both extensive and a state function

answer

What type of property is internal energy?

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

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

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?U = ?H -p?V p is pressure (constant)

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What is the relationship between enthalpy change and internal energy?

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

answer

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

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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

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What is the difference between K and Q?

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Q ; K

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

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Q ; K

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

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?rG = -RT lnK

answer

What is the relationship between ?rG and K?

question

lnK = (?rS/R) - (?rH/RT)

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

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

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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

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True

answer

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

question

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

answer

What is a Daniell cell's cell diagram?

question

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

answer

What is a Galvanic Cell?

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

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What is an Electrolytic Cell?

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Galvanic cells in which the reagents are supplied continuously

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What is a Fuel Cell?

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Left

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During cell notation where is the oxidation half reaction?

question

Right

answer

During cell notation where is the reduction half reaction?

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Left

answer

What side does the anode appear in the cell notation?

question

Right

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What side does the cathode appear in the cell notation?

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

answer

What is the cell notation for a calomel electrode?

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reduction

answer

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

question

?rG = we = -VQ, 1J = 1V x 1C

answer

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

question

?rG will be negative therefore the reaction is spontaneous

answer

If Ecell is positive what will ?rG be?

question

E = hv = hc/ ? , Units: Joules

answer

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

question

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

answer

What is the equation for transmittance?

question

A = - log T

answer

What is the equation for absorbance?

question

T = 0.8 , A= - log (0.8) = 0.1

answer

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

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

answer

What is Beer-Lambert Law? Give units

question

Force exist between the molecules of gasses when Z;1

answer

Repulsive

question

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

answer

Clapeyron equation

question

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

answer

Clausius-Clapeyron equation

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