1. Which of the following is not a state function?

A. Internal energy

B. Enthalpy

C. Entropy

D. Heat

2. A process that occurs at constant pressure is called:

A. Isobaric

B. Isochoric

C. Isothermal

D. Adiabatic

3. Any process that occurs at constant volume is called:

A. Isobaric

B. Isochoric

C. Isothermal

D. Adiabatic

4. A process that occurs at constant temperature is called:

A. Isobaric

B. Isochoric

C. Isothermal D. Adiabatic

5. A process that occurs without heat exchange is called:

A. Isobaric

B. Isochoric

C. Isothermal

D. Adiabatic

6. Which of the following is the correct expression for the change in internal energy (ΔU)?

A. ΔU = q + w
B. ΔU = q - w

C. ΔU = -q + w

D. ΔU = -q - w

7. Which of the following is the correct expression for the change in enthalpy (ΔH)?

A. ΔH = ΔU + PΔV

B. ΔH = ΔU - PΔV

C. ΔH = -ΔU + PΔV

D. ΔH = -ΔU - PΔV

8. Which of the following is the correct expression for the change in entropy (ΔS)?

A. ΔS = qrev/T

B. ΔS = -qrev/T

C. ΔS = qirrev/T

D. ΔS = -qirrev/T

9. Which of the following is the correct expression for the change in Gibbs free energy
(ΔG)?

A. ΔG = ΔH - TΔS

B. ΔG = ΔH + TΔS

C. ΔG = -ΔH + TΔS

D. ΔG = -ΔH - TΔS

10. Which of the following is the correct expression for the equilibrium constant (K)?

A. K = exp(-ΔG°/RT)

B. K = exp(ΔG°/RT)

C. K = -exp(-ΔG°/RT)

D. K = -exp(ΔG°/RT)

11. The standard free energy change for a reaction is given by:

A. ΔG° = -RTlnK
B. ΔG° = RTlnK

C. ΔG° = -RT/lnK

D. ΔG° = RT/lnK

12. The standard free energy change for a reaction is related to the equilibrium constant
by:

A. ΔG° = -RTlnK

B. ΔG° = RTlnK

C. ΔG° = -RT/lnK

D. ΔG° = RT/lnK

13. The standard free energy change for a reaction is a measure of:

A. The spontaneity of the reaction

B. The rate of the reaction

C. The equilibrium constant of the reaction

D. The activation energy of the reaction

14. The standard free energy change for a reaction is related to the equilibrium constant by
the equation:

A. ΔG° = -RTlnK

B. ΔG° = RTlnK

C. ΔG° = -RT/lnK

D. ΔG° = RT/lnK

15. For an irreversible process, the change in entropy of the universe is

16. The change in entropy for an isolated system undergoing a reversible process is:
A. always positive
B. always negative
C. zero
D. can be positive, negative, or zero
E. cannot be determined

17. The ΔG in the process of melting of ice at 0°C is:

18. For the process H₂(g) + Cl₂(g) → 2HCl(g), at 298K and 1 atm, the entropy of the universe
is:
A. ΔSsys > 0 and ΔSsurr > 0
B. ΔSsys < 0 and ΔSsurr > 0
C. ΔSsys < 0 and ΔSuniv < 0
D. ΔSsys > 0 and ΔSsurr < 0

19. A spontaneous reaction is impossible if:

20. A reaction with a low enthalpy of reaction value is non-spontaneous at low temperature
but spontaneous at high temperature. What are the signs for ΔH and ΔS, respectively?
A. positive, negative
B. both negative
C. negative, positive
D. both positive

21. For a system in equilibrium, ΔG is zero under conditions of constant:

22. Which of the following conditions a reaction will be spontaneous at all temperatures?
A. ΔH < 0 and ΔS < 0
B. ΔH < 0 and ΔS > 0
C. ΔH > 0 and ΔS < 0
D. Both B and C
23. Which of the following is the correct criteria for a spontaneous process?
A. ΔSuniv = ΔSsys + ΔSsurr > 0
B. ΔSsys > 0
C. ΔSsurr > 0 only
D. ΔSuniv > 0 only

24. A perfect engine works on a Carnot cycle between 727°C and 127°C. The efficiency is:
A. 82.5%
B. 40%
C. 60%
D. 20%

25. T The direct conversion of A to B is difficult and thus it is converted by path A → C → B.

A. 50 J/mol·K
B. 120 J/mol·K
C. 60 J/mol·K
D. None of the above

26. The entropy change in the fusion of one mole of solid ice melting at 273 K (from latent
heat of fusion 6.0 kJ/mol) is (in J/mol·K):
A. 9 J/mol·K
B. 19.7 J/mol·K
C. 20 J/mol·K
D. 8.3 J/mol·K

27. One mole of an ideal gas at a constant temperature of 297°C is subjected to reversible
non-cyclic isothermal expansion. The change in entropy of expansion is:

A. 101.3 J/mol K

B. 9.5 J/mol K

C. 9.9 J/mol K

D. 0.0 J/mol K

E. None of the above

28. When one mole of an ideal gas is changed according to that of its initial volume and
while reversible, then change in entropy is:

A. 0
B. 8.314 J/mol K

C. 4.157 J/mol K

D. -8.314 J/mol K

29. What is the entropy change when 3.64 g of liquid water is completely converted into
vapor at 100°C? The molar heat of vaporization is 40.67 kJ/mol.

A. 0

B. 40.67 J/mol

C. 40670 J/mol

D. 11.0 J/mol

30. Oxygen gas weighing 6.4 g is expanded from 1 liter to 2 liters at 300°C. What is the
entropy change?

A. 23.94 J/K

B. 46.0 J/K

C. 60 J/K

D. 51.0 J/K

31. What is the ΔG° for the reaction given: CH₄(g) + 2O₂(g) → CO₂(g) + 2H₂O(g) Substance
ΔH° (kJ/mol) S° (J/mol K) CH₄(g) -74.8 186.3 O₂(g) 0 205.0 CO₂(g) -393.5 213.6 H₂O(g) -241.8
188.7

A. -817.9 kJ/mol

B. -817.9 J/mol

C. 817.9 kJ/mol

D. 817.9 J/mol

32. The entropy and enthalpy change for a chemical reaction are -200 J/K mol and +10
kJ/mol, respectively. The nature of reaction is:

A. Spontaneous

B. Reversible

C. Irreversible
D. non-spontaneous

33. Consider a process for what ΔG° = 271 kJ and ΔS° = +57 J/K. How will changing the
temperature affect ΔG for this process?

A. ΔG will increase

B. ΔG will decrease

C. ΔG will remain the same

D. ΔG will not change

34. The effect of 2 moles CO₂ split in the ideal shaft column of compressor of length z = 40
cm at 25°C. The gas was split into the compressor and put into the larger container and put
into the larger container and put into the larger container and the pressure is reversible and
the gas is behaving as an ideal gas?

A. 14.34 J/K B.

16.34 J/K

C. 15.52 J/K

D. 10.20 J/K

35. A sample of perfect gas that initially volume 10 L at 298 K and 1 atm is compressed
isothermally. To what volume must the gas be compressed to reduce its entropy to 5.2 J/K?
A. 1.4 L

B. 8.02 L

C. 40.6 L

D. 5.08 L

36. The entropy change accompanying the transfer of 12,000 J of heat from a body A at
500°C to a body B at 200°C is:

A. +10 J/K B. -10 J/K

C. 27.3 J/K D. -112.5 J/K

37. A non-condensable gas is found:

A. Above the critical point

B. Below the critical point

D. None of these

38. Two moles of an ideal diatomic gas undergoes adiabatic expansion heating from 298 K
to 400 K. The entropy

A. increases by 2R

B. increases by Rln2

C. decreases by 2Rln2

D. decreases by Rln2

39. Given the following entropy values in J/mol K at 298 K: S°(H₂) = 130.6, S°(O₂) = 205.0,
and S°(H₂O) = 69.9. The entropy change in the reaction at 298 K is: 2H₂(g) + O₂(g) → 2H₂O(l)
A. -326.2 J/K

B. -163.1 J/K

C. 163.1 J/K

D. 326.2 J/K

40. What is the free energy change ΔG° when 1 mole of water at 100°C and 1 atm pressure
is converted to its vapor at the same T and P? The heat of vaporization of water at 100°C is
40.67 kJ/mol.

A. zero

B. 0 kJ/mol

C. 40.67 kJ/mol

D. -40.67 kJ/mol

41. At temperature 298 K, the standard enthalpies of CH₄(g), O₂(g), and H₂O(l) are -74.8, 0,
and -286 kJ/mol, respectively. Calculate the change in energy for the formation of water.
Calculate the total change in standard entropy for the reaction: CH₄(g) + 2O₂(g) → CO₂(g) +
2H₂O(l)

42. The ΔH°f for H₂, O₂, and H₂O are 0, 0, and -286 kJ/mol, respectively. Calculate the
standard enthalpy change for the reaction: 2H₂(g) + O₂(g) → 2H₂O(l)
43. A quantity of 1.12 L helium gas is expanded adiabatically to 10 times its volume and
then compressed isothermally to the initial volume. Assume ideal behavior of gas and both
processes are reversible. Calculate the total entropy change of the gas.

44. One mole of ice is converted into water at 273 K and 1 atm. The enthalpies of H₂O(s)
and H₂O(l) are -286 and -286 kJ/mol, respectively. Calculate the entropy change for this
process.

45. Compute the standard free energy of the reaction at 298 K for the combustion of
butane gas using the following data: Species ΔH°f (kJ/mol) S° (J/mol K) C₄H₁₀(g) -125.6
310.2 O₂(g) 0 205.0 CO₂(g) -393.5 213.6 H₂O(l) -285.8 69.9 46. Use the following data to
sketch the phase diagram of carbon disulfide: Triple point: 278.6 K and 1 atm Critical
temperature and pressure: 552 K and 7.8 atm Melting point at the critical pressure: 278.6 K
Vapor pressure of the solid at 101.3 kPa: 12.8 atm

47. Ice and liquid water have equal volumes. They have a critical boiling point. Explain.

48. In liquid water, the freezing temperature is 0°C at 1 atm and 1.00 x 10⁻² atm,
respectively. Use the Clapeyron equation to determine the molar volumes of ice and liquid
water at a pressure of 10 atm, knowing that liquid water has an enthalpy change of 6.00
kJ/kg.

49. The vapor pressure of CCl₄ is 108 mm Hg at 20°C. Calculate the heat of vaporization of
carbon tetrachloride.

50. The heat of fusion of a substance is typically much less than its heat of vaporization.
Explain why that is so.