Physical Chemistry Final

A given amount of real gas compresses adiabatically due to atmospheric pressure from 12.0 L to 3.0 L. Indicate the correct answer referring to the change in internal energy for this process

ΔU = +912 J

A given amount of a liquid substance expands adiabatically against atmospheric pressure from 3.0 L to 12.0 L. Indicate the correct answer referring to the change in internal energy for this process.

ΔU = -912 J.

Indicate the change in internal energy for a chemical system undergoing an adiabatic expansion against vacuum.

∆𝑈=0 for any substance

An isothermal process is used to compress an ideal gas from an initial volume Vito a final volume Vf. What change in internal energy and enthalpy the system will experience?

∆𝑈=0, ∆𝐻=0.

Which of the following is the correct expression for the entropy of an irreversible process occurring in an isolated system?

𝑑𝑆 > 0

Which of the following is the correct expression for the entropy of a reversible process?

𝑑𝑆=𝛿𝑞/𝑇

Indicate the correct result for the total differential of the function𝒇(𝒙,𝒚)=𝟐𝒙^𝟑𝒚𝒛+𝒙𝐥𝐧𝒛

𝑑𝑓(𝑥,𝑦)=(6𝑥^2𝑦𝑧+ln𝑧)𝑑𝑥+(2𝑥^3𝑧)𝑑𝑦

Indicate the correct relationship between the efficiency of an ideal Carnot engine (eC) and the efficiency of a real engine

𝑒c ≥ 𝑒R

In reference to the previous question, one should expect the temperature of the system to...

decrease.

Which of the following is nota state function? a)Internal energy. b)Enthalpy. c)Entropy. d)Helmholtz free energy. e)None, they are all state functions

e) None, they are all state functions

An ideal gas is used to model the behavior of the second step of the Carnot engine. Indicate the correct behavior for the change in entropy for this process.

ΔS = 0.

Consider the Carnot engine and its overall thermodynamic cycle. Indicate the correct set of expressions among the following.

∆𝐺=0, 𝑤<0, 𝑞>0

For an ideal gas undergoing an isothermal reversible process it can be shown that ∆𝑺=𝒏𝑹𝐥𝐧(𝑷𝒊/𝑷𝒇). Which of the following expressions is also correct

∆𝑆= −𝑛𝑅ln(Vf/Vi)

Which of the following is the correct expression for the entropy of an irreversible adiabatic process?

dS > 0

Which of the following is the correct expression for the entropy of an irreversible process?

dS > dq/T

Can the differential df(x,y) = (ax^3 + 2by)dx + (3ax^2y)dy be used to mathematically represent a state function?

NO

What is the percent efficiency of a Carnot cycle working with a hot-reservoir at 200°C and a cold-reservoir at 30°C?

36%

Which of the following processes would cause the Helmholtz free energy to remain constant?

A reversible isochoric and isothermal process

Which of the following statements about the compressibility factor is wrong? A) For an ideal gas, 𝑍<1 B) At high pressures, 𝑍>1 C) The previous statement implies that at high pressures, gas molecules are subject to repulsion D) For 𝑃→0, the ideal gas law holds we can say that 𝑍=1 E) None, the previous statements are all correct

A) For an ideal gas, 𝑍<1

Consider a solid substance. Which of the following expressions is wrong? A) Internal energy increases when the system expands adiabatically. B) Internal energy increases when the system is compressed adiabatically. C) Entropy increases when the system expands. D) Entropy will tend to zero at temperatures approaching 0K. E) None. They are all correct.

A) Internal energy increases when the system expands adiabatically.

Which of the following statements is wrong? A) Temperature is a way of transferring energy. B) Temperature is a measure of the kinetic energy of the particles in the system. C) Temperature is an observable used to compare amount of energy in different systems. D) The previous statement (c) equals to say that a difference in energy tells us about the exchange of energy between the thermodynamic system under investigation and its surroundings. E) Heat is a way of transferring energy.

A) Temperature is a way of transferring energy.

Which of the following statements or expressions does not apply to the concept of "state function"? A) The differential of a state function is inexact B) The differential of a state function is exact C) State functions are thermodynamic properties whose values do not depend on the path D) The previous statement means that state functions are process- independent functions E) We can write Delta T = T_f - T_i only because T is a state function

A) The differential of a state function is inexact

Which of the following statements or expressions describes the work done by the system on the surroundings? A) The system loses energy B) dw = -P_extdV C) dw > 0 D) Answers (A) and (B) are correct E) Answers (A) and (C) are correct

A) The system loses energy

Consider an ideal gas as a closed system behaving adiabatically. Which of the following expressions is wrong? A) dA = -TdS for isothermal processes B) dH = dw + nRdT C) U= U(T) D) U= const for isothermal processes E) dA = 0 for isothermal processes

A) dA = -TdS for isothermal processes

Given the Gibbs free energy as a function of its natural variables, which of the following expressions is wrong? A) dG = -PdV - SdT B) G = G(P,T) C) dG < 0 for isobaric and isothermal processes D) dG = VdP - SdT. E) None. The previous answers are all correct.

A) dG = -PdV - SdT

Which of the following is the wrong expression for the infinitesimal change of enthalpy for an isobaric process? A) dH= dq_r B) dH = dU + PdV C) dH = dw + dq_r + PdV D) dH = -P_extdV + dq_r + PdV E) None, all the above answers are correct

A) dH= dq_r

What is the value of the Joule-Thompson coefficient for an ideal gas? A) u_jt = 0 B) u_jt > 0 C) u_jt < 0 D) The Joule-Thompson experiment refers to the behavior of real gases. As such, the concept of Joule-Thompson coefficient is not applicable to ideal gasses. E) According to the several thermodynamic conditions which can occur, answers (A), (B), and (C) may all apply at any given time

A) u_jt = 0

What is the change in enthalpy for an ideal gas that expands from 1.0 dm3 to 2.0 dm3 as a consequence of an isothermal process? A) ΔH = 0. B) ΔH > 0. C) ΔH < 0. D) I cannot tell because I do not have any information to determine the work done by the system on the surroundings. E) I cannot tell because I do not have any information about the internal energy and the amount of substance.

A) ΔH = 0.

An ideal gas expands from 2.0 L to 3.0 L. If the process is isothermal, what changes in internal energy and enthalpy the system will experience? A) ΔU = 0, ΔH = 0. B) ΔU = 0, ΔH < 0. C) ΔU > 0, ΔH = 0. D) I cannot tell because I do not have any information about the work done by the surroundings on the system. E) I cannot tell because I do not have any information about the exchange of heat.

A) ΔU = 0, ΔH = 0.

Given the Gibbs free energy as a function of its natural variables, which of the following expressions is wrong? A) 𝑑𝐺=−𝑃𝑑𝑉−𝑆𝑑𝑇 B) 𝐺≡𝐺(𝑃,𝑇) C) (𝑑𝐺)P,T <0 is the spontaneous condition D) 𝑑𝐺 = 𝑉𝑑𝑃−𝑆𝑑𝑇 E) dG = (dG/dP)T dP + (dG/dT)P dT

A) 𝑑𝐺=−𝑃𝑑𝑉−𝑆𝑑𝑇

Under which thermodynamic conditions the enthalpy for a liquid substance remains constant during a reversible process? A)

Adiabatic and isobaric

An ideal gas is used to model the behavior of the first step of the Carnot engine. Indicate the correct behavior for the change in the Helmholtz free energy for this specific step.

Af < Ai

Which of the following observables can never be negative? A) A change in Gibbs free energy for a given reaction. B) A change in entropy for an isolated system. C) A change in chemical equilibrium. D) A change in internal energy for an ideal gas. E) All the listed observables can show both negative and negative values with respect to the indicated conditions.

B) A change in entropy for an isolated system.

Why can it be useful to determine the Boyle Temperature? A) Because at that temperature, the van der Waals equation can be applied B) Because at that temperature the virial coefficients are zero and we can use the ideal gas law to describe the behavior of a real gas C) Because at that temperature the van der Waals constants are zero and we can use the ideal gas law to describe the behavior of a real gas. D) Because all the real gasses have the same Boyle temperature and this allows us to use the ideal gas law to study real gasses E) Because at that temperature the zeroth law of thermodynamics is verified.

B) Because at that temperature the virial coefficients are zero and we can use the ideal gas law to describe the behavior of a real gas

Which of the following is not a state function? A) Pressure B) Mechanical work C) Enthalpy D) Temperature E) None; they are all state functions

B) Mechanical work

Which of the following statements does not apply to the definition of an ideal gas? A) Intermolecular interactions are negligible. B) The Gibbs free energy depends on temperature only. C) The enthalpy depends on temperature only. D) The internal energy depends on temperature only. E) None. The previous answers are all correct.

B) The Gibbs free energy depends on temperature only.

How would you "read" the definition of mechanical work written as w = -Pext·ΔV and leading to the result w < 0 ? A) This integrated expression for mechanical work is the product of the external constant pressure and the change in volume. The fact that w<0 means that the surroundings are losing energy. B) This integrated expression for mechanical work is the product of the external constant pressure and the change in volume. The fact that w<0 means that the system is losing energy. C) This is the work performed by the system on the surroundings. This is why P_ext appears in the expression. D) The formula must be read from the view point of the surroundings. This is why P_ext appears in the expression. E) These expressions indicate that the mechanical work performed increases the energy of the system which represents always our point of view.

B) This integrated expression for mechanical work is the product of the external constant pressure and the change in volume. The fact that w<0 means that the system is losing energy.

Which of the following is the correct expression for an infinitesimal change in enthalpy for an adiabatic mechanically reversible process? (Canvas has a bug that currently doesn't allow me to visualize Greek letters. Please, consider the notation "dw" and "dq" as correct.) A) dH = d(PV) B) dH = VdP. C) dH = dU + d(PV). D) dH = -PdV + dq E) dH = 0.

B) dH = VdP.

Which of the following statements or expressions describes the work done by the surroundings on the system? A) The system loses energy B) dw = -P_extdV C) dw > 0 D) Answers (A) and (B) are correct E) Answers (A) and (C) are correct

B) dw = -P_extdV

Given the virial equation expressed as a power series of the molar volume, indicate the correct units for the third virial coefficient B_3V(T)

B_3V(T) can be expressed as L^2 *mol ^-2

The van der Waals equation corrects the ideal gas law because.... A) ... it takes into account the fact that the particles of the system do not have a volume B) ... it takes into account the fact that experimentally it is easier to work at constant pressure than at constant volume C) ... it takes into account the fact that the particles of the system have a volume but they do interact D) ... it takes into account the fact that the particles of the system have a volume but they do not interact E) ... it takes into account the fact that the compressibility factor can be written as a power series in V or P.

C) ... it takes into account the fact that the particles of the system have a volume but they do interact

A chemical system undergoes a mechanical irreversible expansion when... A) ... the pressure of the system equals the pressure of the surroundings B) ... the pressure of the system is less than the pressure of the surroundings C) ... the pressure of the system is much greater than the pressure of the surroundings D) ... the external pressure is much greater than the internal pressure E) ... system and surroundings are in thermal equilibrium

C) ... the pressure of the system is much greater than the pressure of the surroundings

Which of the following ways of stating the 1st law of thermodynamics is wrong? A) Delta U = w + q B) The previous answer means that a finite change in thermal energy is given by the sum of work and heat C) Delta U = Delta w + Delta q D) dU = dw + dq E) None, they are all correct

C) Delta U = Delta w + Delta q

Which of the following statements is correct? A) For ideal gases, internal energy and enthalpy are functions of temperature and volume B) For ideal gases, internal energy and enthalpy are functions of temperature and pressure C) For ideal gasses (dU/dV)T = (dH/dP)T = 0 D) For real gasses (dU/dV)T = (dH/dP)T = 0 E) For real gasses, dU =CvdT and dH = CpdT

C) For ideal gasses (dU/dV)T = (dH/dP)T = 0

Given the virial equation expressed as a power series of the molar volume, indicate the correct units for the third virial coefficient 𝑩𝟑𝑷(𝑻). A) 𝐵_3P(𝑇)can be expressed in atm^-3 B) 𝐵_3P(𝑇)can be expressed in bar^-3 C) The previous two answers are both correct D) 𝐵_3P(𝑇) is unitless because is a coefficient. E) 𝐵_3P(𝑇)must be expressed in K because is a function of the temperature

C) The previous two answers are both correct

Which is the correct expression for the change in internal energy for a gas undergoing an isochoric and adiabatic process? A) ΔU = w. B) ΔU = q C) ΔU = 0 D)ΔU = -PΔV + q E)I do not have enough information to tell

C) ΔU = 0

Which of the following expressions for various form of energies is wrong? A) U = const for an isolated system. B) +w = -q or -w = +q, for an isolated system. C) ΔU = Δw for an adiabatic process. D) H = const for a cyclic process. E) ΔU = w for an adiabatic process.

C) ΔU = Δw for an adiabatic process.

Complete the sentence "Pressure is... A) ...a vector." B) ...a scalar quantity given by an applied force translating into a positive displacement." C) ...a vector but for convenience we treat it as a scalar." D) ...a scalar defined as the amount of force acting per unit area." E) ...a scalar defined as the amount of force acting per unit of volume."

D) ...a scalar defined as the amount of force acting per unit area."

How can you increase the entropy of a chemical system? A) I can add substance to the system B) I can increase the temperature of the system C) I can increase the volume of the system D) All of the above E) None of the above

D) All of the above

Consider an ideal gas. Which of the following statements is correct? A) An ideal gas is 100%compressible B) 𝑈=𝑈(𝑇), 𝐻=𝐻(𝑇) C) 𝑑𝑈=0 D) Answers (a) and (b) are both correct. E) Answers (b) and (c) are both correct

D) Answers (a) and (b) are both correct.

From what we have seen so far in this course, which of the following expressions of the internal energy is wrong? A) dU = (dU/dT)V dt + (dU/dV) T dV B) Delta U = 0 for a liquid substance undergoing an isochoric adiabatic process C) Delta U = 0 for an ideal gas undergoing an isothermal process D) Delta U = 0 for an ideal gas behaving as a closed system E) Delta U = 0 for a liquid substance undergoing a cyclic process

D) Delta U = 0 for an ideal gas behaving as a closed system

Which of the following observables does not appear in an equation of state (EOS)? A) Temperature B) Pressure C) Volume D) Energy E) Amount of substance

D) Energy

In reference to internal energy, enthalpy, entropy, Helmholtz energy, and Gibbs free energy, which of the following statements is wrong? A) They are all exact differentials. B) They are all path-independent functions C) We were able to individuate for each of them the proper natural independent variables from which equilibrium and spontaneous conditions arise. D) Given the proper thermodynamic conditions, they all obey to the same spontaneous condition. E) For a closed thermodynamic cycle: ΔU = ΔH = ΔS = ΔA = ΔG = 0.

D) Given the proper thermodynamic conditions, they all obey to the same spontaneous condition.

Which of the following statements about "mechanical work" is wrong? A) Mechanical work is a scalar quantity. B) Mechanical work can be expressed in units of atm·L. C) Mechanical work has the unit of an energy. D) Mechanical work is a path-independent function. E) Mechanical work is a path-dependent function.

D) Mechanical work is a path-independent function.

Indicate the correct sequence that defines the terms: isochoric, isobaric, isothermal. A) Same T, Same V, Same P B) Same P, Same V, Same T C) Same T, Same P, Same V D) Same V, Same P, Same T E) Same V, Same T, Same P

D) Same V, Same P, Same T

Which of the following statements about the Carnot cycle is wrong? A) Decreasing the temperature of the cold reservoir of a Carnot cycle engine will increase the efficiency of the engine. B) Increasing the temperature of the hot reservoir of a Carnot cycle engine will increase the efficiency of the engine. C) The Carnot cycle is, by construction, a reversible cycle. D) Since the Carnot cycle is a cyclic process, the overall work done in such a cycle is zero E) A Carnot machine will always have a higher efficiency than a real machine

D) Since the Carnot cycle is a cyclic process, the overall work done in such a cycle is zero

Indicate the wrong statement among the following. A) A free expansion is a spontaneous process. B) A free expansion is an irreversible process. C) When a free expansion occurs, the system does not perform any work on the surroundings. D) Statement (c) is a consequence of the fact that ΔV = 0. E) Statement (c) is a consequence of the fact that P_ext = 0.

D) Statement (c) is a consequence of the fact that ΔV = 0.

Which of the following statements about the 0th law of thermodynamics is correct? A) This law refers to open systems where both energy and matter can be exchanged with the surroundings B) This law refers to isolated systems where neither energy nor matter can be exchanged with the surroundings. C) This law refers to all kind of systems: open, isolated, and closed. D) This law refers to closed systems where only energy in form of heat can be exchanged with the surroundings E) This law refers to thermal equilibrium among different systems in contact but it represents a mere theoretical statement that does not have any practical application.

D) This law refers to closed systems where only energy in form of heat can be exchanged with the surroundings

Which of the following statements about the concept of "mechanical work" is wrong? A) Mechanical work is a not a vector. B) Mechanical work can be expressed in units of atm·L . C) Mechanical work is a scalar. D) When mechanical work is done by the system on the surroundings, the system gains mechanical energy. E) When mechanical work is done by the system on the surroundings, the system loses mechanical energy.

D) When mechanical work is done by the system on the surroundings, the system gains mechanical energy.

The expression w_rev =-nRTln(V_f/V_i) holds for... A) an ideal gas undergoing a mechanical reversible process B) an ideal gas undergoing a mechanical reversible compression C) an ideal gas undergoing an isothermal mechanically reversible expansion D) an ideal gas undergoing an isothermal mechanically reversible process E) any gas undergoing an isothermal mechanically reversible process

D) an ideal gas undergoing an isothermal mechanically reversible process

What expression for the enthalpy would you use to study an isobaric mechanically reversible process? (Canvas has a bug that currently doesn't allow me to visualize Greek letters. Please, consider the notation "dw" and "dq" as correct.) A) dH = dU + PdV. B) dH = dw + dq + d(PV). C) dH = dq + PdV. D) dH = dq_p E) dH = 0.

D) dH = dq_p

The equation Delta U= q_v means that A) the system undergoes an adiabatic process B) the system is closed C) the surroundings and the system are in thermal equilibrium D) the system undergoes an isochoric process E) the system undergoes an isochoric expansion

D) the system undergoes an isochoric process

Which of the following statements about entropy is correct? A) A change in a closed system from an initial to a final state produces a greater increase in entropy when carried out irreversibly than when done reversibly. B) ΔS = 0 for a closed system undergoing an adiabatic process. C) ΔS = 0 for a closed system undergoing a reversible process. D) ΔS = 0 for a closed system undergoing a reversible and adiabatic process. E) ΔS < 0 for an isolated system undergoing a reversible process

D) ΔS = 0 for a closed system undergoing a reversible and adiabatic process.

Which of the following ways of stating the 1st law of thermodynamics is wrong? A) ∆𝑈=𝑤+𝑞 B) The previous answer means that a finite change in internal energy is given by the sum of work and heat C) 𝑑𝑈=𝛿𝑤+𝛿𝑞 D) ∆𝑈=∆𝑤+∆𝑞 E) ∆𝑈=0for isolated systems

D) ∆𝑈=∆𝑤+∆𝑞

Given the Helmholtz free energy as a function of its natural variables, which of the following expressions is wrong? A) 𝑑𝐴= −𝑃𝑑𝑉−𝑆𝑑𝑇 B) 𝑑𝐴=𝛿𝑤 for isothermal reversible processes C) (𝑑𝐴)V,T <0 is the spontaneous condition D) 𝑑𝐴 = 𝑉𝑑𝑃−𝑆𝑑𝑇 E) dA = (dA/dV)T dV + (dA/dT)V dT

D) 𝑑𝐴 = 𝑉𝑑𝑃−𝑆𝑑𝑇

An isothermal process is used to compress an ideal gas from an initial volume V1 to a final volume V2. What change in internal energy and enthalpy will the system experience?

Delta U = 0, Delta H = 0

Consider an ideal gas. Which of the following statements is correct? A) U = U(T), H = H(T) B) dU = 0 C) An ideal gas is 100% compressible D) Answers (A) and (B) are both correct E) Answers (A) and (C) are both correct

E) Answers (A) and (C) are both correct

Which of the following expressions for the First Law of Thermodynamics is wrong? A) dU =dq - dw B) dU = TdS - PdV for a reversible process C) dU = TdS - P_extdV for a mechanically irreversible process D) Answers (A) and (B) are both wrong E) Answers (A) and (C) are both wrong

E) Answers (A) and (C) are both wrong

Consider 1 L of Argon as a closed system and as an ideal gas undergoing an isothermal expansion. Which of the following expressions can be used to describe its thermodynamic state? A) PV=R B) PV=const C) P is inverse proportional to V D) Answers (A) and (B) are both correct and they give the same information about the system under investigation E) Answers (B) and (C) are both correct and they give the same information about the system under investigation.

E) Answers (B) and (C) are both correct and they give the same information about the system under investigation.

Which of the following statements is true for a thermodynamic system? A) For a process occurring in a closed system, both energy and matter can be exchanged with the surroundings. B) For a process occurring in a closed system, only energy can be exchanged with the surroundings. C) An isolated system is a closed system where no energy is exchanged with the surroundings. D) A closed system is also an isolated system. E) Answers (b) and (c) are both correct.

E) Answers (b) and (c) are both correct.

Consider a closed system undergoing an adiabatic mechanically reversible process. Which of the following expressions for the internal energy is wrong? A) dU = dw B) dU = -P_extdV C) Delta U = -PDeltaV D) Delta U = -nRTln(V_f/V_i) E) As a matter of fact, answers (B), (C), and (D) are wrong

E) As a matter of fact, answers (B), (C), and (D) are wrong

Indicate the change in internal energy for a chemical system undergoing an adiabatic expansion against a vacuum A) Delta U = +w B) Delta U = -w C) Delta U = -q D) Delta U = 0 if the system is an ideal gas E) Delta U = 0

E) Delta U = 0

Consider the van der Waals equation. Which of the following statements is wrong? A) "a" considers the interaction between the particles B) "b" considers the size of the particles C) "b" corrects the volume corresponding to the ideal cause D) "a" and "b" are species-dependent constants E) None, all the above answers are correct

E) None, all the above answers are correct

Which of the following expressions for the change in enthalpy is wrong? A) dH = -P_extdV + TdS _d(PV) B) dH = 0 for a reversible adiabatic isobaric process C) dH =TdS + VdP for a mechanically reversible process D) dH = TdS for a mechanically reversible isobaric process E) None, all the previous answers are correct

E) None, all the previous answers are correct

Which of the following statements does not correspond to the qualitative description we gave of the Lennard-Jones potential A) Repulsion forces dominate at short distances B) Attraction forces dominate at medium/long distances C) At dissociation, the atoms do not experience either attraction or repulsion D) When repulsion and attraction forces balance each other, the molecule is at equilibrium E) None, all the previous statements are correct.

E) None, all the previous statements are correct.

Which of the following statements about the compressibility factor is wrong? A) For an ideal gas, Z = 1 B) At high pressures, Z > 1 C) The previous statement implies that at high pressures, gas molecules are subject to repulsion D) For P -> 0, the ideal gas law holds we can say that Z=1 E) None, the previous statements are all correct

E) None, the previous statements are all correct

Which of the following expressions or statements does not apply to an ideal gas? A) PdV = nRdT for a closed system undergoing an isobaric process. B) Z = 1. C) dA = 0 for an adiabatic isothermal process D) dG = 0 for an adiabatic isothermal process. E) None, they are all correct.

E) None, they are all correct.

Consider a solid substance. Which of the following expressions is wrong? A) ΔS = 0 for a reversible adiabatic process B) ΔS > 0 when the system absorbs heat. C) ΔS > 0 when the system expands. D) ΔS < 0 when the system is compressed E) None. They are all correct.

E) None. They are all correct.

Which of the following statements is wrong? (Canvas seems to have a bug that currently doesn't allow me to visualize greek letters. Please, consider the notation "dw" and "dq" as correct.) A) dH = dq + VdP for a reversible process B) dH = PdV + VdP for an adiabatic expansion against vacuum. C) dU = dq for an expansion against vacuum. D) dU = 0 for an adiabatic expansion against vacuum. E) None. They are all correct.

E) None. They are all correct.

Based on what we have seen so far in the course, which of the following expressions for the internal energy is correct? A) U = U(T,V) for a solid substance. B) dU = 0 for any substance undergoing an isochoric adiabatic process. C) dU = 0 for an isolated system. D) None, the previous statements are all wrong. E) The first three statements are correct.

E) The first three statements are correct.

Considering the compressibility factor which of the following statements is wrong? A) Z = 1 for an ideal gas. B) Z > 1 at high pressures. C) The previous statement (b) implies that gas molecules are subject to repulsion. D) Z < 1 at intermediate pressures. E) The previous statement (d) implies that gas molecules are subject to repulsion.

E) The previous statement (d) implies that gas molecules are subject to repulsion.

Consider a liquid substance undergoing a reversible expansion. Which of the following expressions for the change in enthalpy is definitively wrong? (Canvas seems to have a bug that currently doesn't allow me to visualize greek letters. Please, consider the notation "dw" and "dq" as correct.) A) dH = dU + PdV + VdP B) dH = dU + d(PV) C) dH = dq + VdP D) dH = -PdV + dq + d(PV) E) dH = dq + d(PV).

E) dH = dq + d(PV).

Consider an ideal gas as closed system. Which of the following expression is wrong? (Canvas seems to have a bug that currently doesn't allow me to visualize greek letters. Please, consider the notation "dw" and "dq" as correct.) A) dU = 0 for an isothermal process. B) H = H(T) C) dH = 0 for an isothermal process. D) w < 0 when the system expands. E) dq = 0.

E) dq = 0.

Which of the following statements referring to internal energy, enthalpy, entropy, Helmholtz energy, and Gibbs free energy is correct?

For a thermodynamic cycle: ∆𝑈=∆𝐻=∆𝐴=∆𝐺=∆𝑆=0

An ideal gas is used to model the behavior of the first step of the Carnot engine. Indicate the correct behavior for the change in enthalpy for this specific step

Hf = Hi

Which are the SI units of heat, molar enthalpy, temperature, and molar heat capacity respectively?

J , J/mol , K , J/(K * mol)

Which are the SI units of work, molar Gibbs free energy, entropy, and heat capacity, respectively?

J, J/mol, J/K, J/K.

Which of the following is one of the possible correct statements of the 3rd law of thermodynamics?

Lim (T - 0K) S(T) = 0 for a perfect crystalline system.

.When an increase in temperature is experienced, a given amount of ice melts into liquid water at 273.15 K, and then vaporizes at 373.15 K. Assuming that the overall process occurs at standard pressure, indicate the correct trend for entropy

S(s) <𝑆(l) ≪ 𝑆(g)

An ideal gas is used to model the behavior of the first step of the Carnot engine. Indicate the correct behavior for the change in entropy for this specific step.

Sf > Si

Which of the following is the correct expression for the entropy of a reversible process?

dS = dq/T

Which of the following statements referring to the 0th law of thermodynamics is correct?

This law refers to two closed systems exchanging heat

Can the differential 𝒅𝒇(𝒙,𝒚)=(𝟐𝒙𝒚)𝒅𝒙+(𝒙𝟐+𝟑𝒚𝟐)𝒅𝒚be used to mathematically represent a state function?

Yes

Which of the following statements or expressions describes the work done by the system on the surroundings?

b) 𝑤<0

Which of the following statements or expressions describes the work done by the surroundings on the system?

c) 𝑤>0

Pick the correct and most simplified expression describing an infinitesimal change in enthalpy for a solid substance undergoing an isobaric mechanically reversible process?

dH = dq_p

Which of the following is the correct expression for the entropy of a reversible adiabatic process?

dS = 0

Consider the Carnot engine and its overall thermodynamic cycle. Indicate the correct set of expressions among the following

dS = 0, dw < 0, dq > 0

Which of the following expressions is equivalent to w_rev = -nRTln(V_f/V_i)?

w_rev = nRTln(P_f/P_i)

Which of the following expressions is equivalent to w_rev = -nRTln(v_f/V_i)

w_rev = nRTln(P_f/P_i)