PPSC Chemistry Lecturer Preparation (Test # 05)- Malik Xufyan 03137355727

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PPSC CHEMISTRY CLASS
Test Session
CH: Thermodynamics
Test # 05
For more WhatsApp # 0313-7355727
Topics:
1. First law of thermodynamics
2. Enthalpy change
3. Entropy
4. Second law of thermodynamics
First Law of Thermodynamics
1. The first law of thermodynamics is_______
(a) the total energy of an isolated system remains constant though it may change from one
form to another.
(b) total energy of a system and surroundings remains constant
(c) whenever energy of one type disappears, equivalent amount of another type is produced
(d) all of the above
2. Thermodynamics is applicable to_______
(a) microscopic systems only
(b) macroscopic systems only
(c) homogeneous systems only
(d) heterogeneous systems only
3. The mathematical relation for the first law of thermodynamics is_______
(a) ΔE = q – w
(b) ΔE = 0 for a cyclic process
(c) ΔE = q for an isochoric process
(d) all of these
4. Which of the following properties is not a function of state?
(a) concentration
(b) internal energy
(c) enthalpy
(d) entropy
5. A system that can transfer neither matter nor energy to and from its surroundings is
called_______
(a) a closed system
(b) an isolated system
(c) an open system
(d) a homogeneous system

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6. Zinc granules reacting with dilute hydrochloric acid in an open beaker consti-
tutes_______
(a) an isolated system
(b) an open system
(c) a closed system
(d) a heterogeneous system
7. An intensive property does not depend upon_______
(a) nature of the substance
(b) quantity of matter
(c) external temperature
(d) atmospheric pressure
8. Which of the following sets of properties constitute intensive properties?
(a) temperature, pressure and volume
(b) mass, density and volume
(c) density, pressure and temperature
(d) internal energy, density and pressure
9. Which out of the following is incorrect?
(a) heat flow into the system is +ve
(b) heat flow out of the system is –ve
(c) work done on the system is –ve
(d) none of these
10. For a cyclic process, the change in internal energy of the system is_______
(a) always positive
(b) always negative
(c) equal to zero
(d) equal to infinity
11. The work done when 1 mole of a gas expands reversibly and isothermally from 5
atm to 1 atm at 300 K is_______
(a) – 4015 J
(b) +4015 J
(c) zero
(d) 150 J
12. A system in which state variables have constant values throughout the system is
called in a state of_______
(a) equilibrium
(b) non-equilibrium
(c) isothermal equilibrium
(d) none of these
13. A gas expands from 10 litres to 20 litres against a constant external pressure of 10
atm. The pressurevolume work done by the system is_______
(a) 100 lit atm
(b) –100 lit atm
(c) 10 lit atm
(d) –10 lit atm
14. One mole of an ideal gas at 300 K is expanded isothermally from 1 litre volume to 10
litre volume. ΔE for this process is_______ (R = 2 cal K–1 mol–1)
(a) 300 cal
(b) 600 cal
(c) 1200 cal
(d) 0 cal

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15. A system absorbs 100 kJ heat and performs 50 kJ work on the surroundings. The
increase in internal energy of the system is_______
(a) 50 kJ
(b) 100 kJ
(c) 150 kJ
(d) 5000 kJ
16. The work done when 1 mole of a gas expands reversibly and isothermally from 5
atm to 1 atm at 300 K is_______
(a) – 4015 J
(b) +4015 J
(c) zero
(d) 150 J
17. Three moles of an ideal gas (Cv = 5 cal K–1 mol–1) at 10.0 atm and 0° are converted to
2.0 atm at 50°. The ΔE for the process is_______
(a) 150 cal
(b) 300 cal
(c) 750 cal
(d) 1500 cal
Enthalpy change
18. The change in enthalpy of a system is measured by measuring_______
(a) heat of the process at constant volume
(b) heat of the process at constant temperature
(c) heat of the process at constant pressure
(d) none of these
19. The enthalpy change, ΔH of a process is given by the relation_______
(a) ΔH = ΔE + p Δv
(b) ΔH = ΔE + Δn R T
(c) ΔH = ΔE + w
(d) all of these
20. The enthalpy change of a reaction is independent of_______
(a) state of the reactants and products
(b) nature of the reactants and products
(c) initial and final enthalpy change of the reaction
(d) different intermediate reaction
21. The amount of heat required to raise the temperature of one mole of the substance
by 1 K is called_______
(a) heat capacity
(b) molar heat capacity
(c) molar heat
(d) molar capacity
22. Heat capacity at constant volume is the change in_______
(a) internal energy with temperature at constant volume
(b) internal energy with temperature at constant pressure
(c) enthalpy with temperature at constant volume
(d) enthalpy with temperature at constant pressure
23. Heat capacity at constant pressure is the change in_______
(a) internal energy with temperature at constant volume
(b) internal energy with temperature at constant pressure

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(c) enthalpy with temperature at constant volume
(d) enthalpy with temperature at constant pressure
24. For the reaction H2 + I2 → 2HI, ΔH is equal to_______
(a) ΔE + 2 R T
(b) ΔE – 2 R T
(c) ΔE
(d) ΔE + R T
25. Which of the following relations is true ?
(a) Cp > Cv
(b) Cv > Cp
(c) Cp = Cv
(d) Cp = Cv = 0
26. The heat capacity at constant pressure is related to heat capacity at constant volume
by the relation_______
(a) Cp – R = Cv
(b) Cv – R = Cp
(c) Cp – Cv = R
(d) R – Cp = Cv
27. The standard enthalpy change of combustion occurs when 1 mol of substance is
burnt more than
(a) nitrogen
(b) oxygen
(c) carbon dioxide
(d) helium
28. The enthalpy changes which cannot be found by calorimeter can be found by the
help of
(a) Newton's Law
(b) Hess's Law
(c) Krebs's Law
(d) Ohm's Law
29. The enthalpy change when the number of reactants gives products under standard
conditions is called standard enthalpy change of
(a) reaction
(b) formation
(c) combustion
(d) neutralization
30. The enthalpy changes of combustion are
(a) endothermic
(b) exothermic
(c) ectothermic
(d) hypothermic
31. The energy which is required to elevate the temperature of 1g of liquid by 1 °C is
called
(a) ideal heat capacity
(b) specific heat capacity
(c) latent heat capacity
(d) specific latent heat capacity
32. The standard enthalpy change information of any element in the standard state is
(a) unit
(b) zero

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(c) stable
(d) unstable
33. Enthalpy change of atomization involves the production of gaseous atoms from its
(a) atoms
(b) solute
(c) reactants
(d) products
34. The technique which we use to measure enthalpy change of reactions is known as
(a) spectrometry
(b) calorimetry
(c) stoichiometry
(d) geoalgometry
35. Anhydrous calcium chloride (CaCl2) and water (H2O) react together to heat the
food by
(a) endothermic
(b) exothermic
(c) ectothermic
(d) hypothermic
36. The chemical reactions which emit energy to surroundings are called
(a) endothermic
(b) exothermic
(c) ectothermic
(d) hypothermic
37. The increasing order of enthalpy of vaporization of NH3, PH3, and AsH3 is
(a) NH3 , AsH3 , PH3
(b) NH3 , PH3 , AsH3
(c) AsH3 , PH3 , NH3
(d) PH3 , AsH3 , NH3
38. In Born-Haber cycle, the sum of the enthalpy changes around a cycle is
(a) Zero
(b) negative
(c) positive
(d) constant
39. The enthalpies of fusion for all reactions are always
(a) Zero
(b) negative
(c) positive
(d) constant
Entropy and 2nd Law of Thermodynamics
40. Second law of thermodynamics defines
(a) Work
(b) Heat
(c) Entropy
(d) Internal Energy
41. Entropy change is quantitative statement of second law of thermodynamics.
(a) True
(b) False
42. In an adiabatic process _______ can flow into or out of the system.

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(a) no heat
(b) heat
(c) matter
(d) no matter
43. Which is true for an isobaric process?
(a) dp > 0
(b) dp < 0
(c) dp = α
(d) dp = 0
44. An isochoric process takes place at constant_______.
(a) volume
(b) temperature
(c) pressure
(d) concentration
45. The work done in the reversible expansion of a gas from the initial state A to final
state B is_______
(a) maximum
(b) minimum
(c) equal to zero
(d) equal to infinity
46. The change in internal energy for an isobaric process is given by_______
(a) ΔE = q + p Δv
(b) ΔE = q – p Δv
(c) ΔE = q
(d) ΔE = p Δv
47. Which of the following relations is applicable to adiabatic expansion of an ideal gas?
(a) T1 V1
γ–1
= T2 V2 γ–1
(b) P1 V1
γ
= P2 V2 γ
(c) both
(d) none of these
48. Which of the following laws was formulated by Nernst?
(a) First law of thermodynamics
(b) Second law of thermodynamics
(c) Third law of thermodynamics
(d) None of the above
49. In a cyclic heat engine there is
(a) net heat transfer to the system and net work transfer from the system
(b) net heat transfer from the system and net work transfer to the system
(c) depends on the conditions of cycle
(d) none of the mentioned
50. The function of a heat engine cycle is to _____ continuously at the expense of _____
to the system.
(a) heat input, produce work
(b) produce work, heat input
(c) can be both of the mentioned
(d) none of the mentioned
51. For spontaneous adsorption of gas
(a) ΔS is negative so ΔH should be highly positive
(b) ΔS is negative so ΔH should be highly negative
(c) ΔS is positive so ΔH should also be highly positive

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(d) ΔS is positive so ΔH should be negative
52. For which of the following conditions a reaction will be spontaneous at all the tem-
perature?
(a) ΔH < 0 and ΔS < 0
(b) ΔH < 0 and ΔS = 0
(c) ΔH < 0 and ΔS > 0
(d) both (b) and (c)
53. Which of the following is the correct criteria for a spontaneous process?
(a) ΔSsystem – ΔSsurroundings > 0
(b) ΔSsurroundings > 0 only
(c) ΔSsystem + ΔSsurroundings > 0
(d) ΔSsystem > 0 only
54. Which of the following is true for the entropy of an isolated system?
(a) It can never increase
(b) It can never decrease
(c) It can never be zero
(d) None of the above
55. Which of the following is correct for the net entropy change in an irreversible pro-
cess?
(a) It is positive
(b) It is negative
(c) It is zero
(d) All of the above
(d) none of the mentioned
56. Entropy change is depend on .....
(a) Mass transfer
(b) Heat transfer
(c) Work transfer
(d) Pressure transfer
57. Entropy of universe tends to
(a) Remain constant
(b) Become zero
(c) Be maximum
(d) None of above
58. Entropy is ................... property.
(a) Intensive
(b) Extensive
(c) Both A and B
(d) None of these.
59. At triple point entropy is..........
(a) Minimum
(b) Maximum
(c) Zero
(d) None of these
60. What is unit of entropy
(a) J / k
(b) J/ kg I
(c) Kg / mol
(d) Joule