CHEM 241
CHEMICAL THERMODYNAMICS
Close Bok Exam (1)
Time : 60 min
2009 – 2010 2nd term
Name:
Useful information
Number:
R = 0.08206 L atm mol–1 K–1,
Section:
1 atm = 1.01325×105 Pa,
1atm = 76 cmHg
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R= 8.314 J mol–1 K–1
1atm = 760 mmHg
Directions: For each of the following questions, choose the letter that best answers the question and
place it on your answer sheet.
(1) Choose the incorrect statement
(A) Open systems can exchange both energy and matter with its surroundings.
(B) Closed systems can only exchange energy and do not exchange matter
with its surroundings.
(C) Isolated systems can exchange energy and matter with its surroundings. #
(D) None of the above.
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(2) Which of the following is not an intensive property?
(A) enthalpy #
(B) Density
(C) Temperature
(D) Specific volume
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(3) Which of the following is an extensive property?
(A) Entropy
(B) Enthalpy
(C) Volume
(D) All of the above. #
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(4) In which of the following processes, dT =0?
(A) Adiabatic process
(B) Isobaric process
(C) Isothermal process #
(D) Isochoric process
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(5) An Ideal gas undergoes an adiabatic process. Its internal energy increases by
100 J. Which of the following accurately describes the work done and heat
exchanged?
(A) 100 J of work done by the process; 0 J of heat exchanged.
(B) 100 J of work done by the process; 100 J of heat exchanged.
(C) 100 J of work done on the process; 0 J heat exchanged. #
(D) 50 J of work done on the process; 50 J of heat exchange.
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(6) If the systems A and B are in thermal equilibrium with system C, then system A
is also in thermal equilibrium with system B. In thermodynamics, this statement
is known as
(A) 1st law
(B) 2nd law
(C) 3rd law
(D) zeroeth law #
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(7) The work done during the free expansion of an ideal gas is equal to
(A) Pext
(B) dV
(C) dE
(D) zero #
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(8) The work done during isothermal irreversible change will be given by
(A)  Pext (V f  Vi ) #
(B)  nRT ln
(C) nRT ln
Vf
Vi
Pf
Pi
(D) Zero
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(9) Two litres of an ideal gas at a pressure of 10 atm expands isothermally against
space until its total volume becomes 100 litres. The amount of heat absorbed in
the expansion is
(A) 2.303 J
(B) 100 J
(C) Zero #
(D) 90 J
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(10) Which of the following statements is true
(A) The work done in reversible expansion is less than the work done in
irreversible expansion.
(B) The work done in reversible expansion is equal to the work done in
irreversible expansion.
(C) The work done in reversible expansion is greater than the work done in
irreversible expansion. #
(D) All.
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(11) The amount of heat exchanged between system and surroundings under constant
pressure is called
(A) Entropy
(B) Enthalpy #
(C) Internal energy
(D) Free energy
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(12) A gas is allowed to expand from a volume of 1.0 L to 10.1 L against an external
pressure of 0.50 atm. If the gas absorbs 250 J of heat from the surroundings,
what are the values of q, w, and E respectively?
(A) 250 J, -461 J, -211 J #
(B) -250 J, -461 J, -711 J
(C) 250 J, -461 J, -711 J
(D) 250 J, -4.55 J, 245 J
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(13) Consider an isobaric compression (cooling from T1 to T2) of 0.450 mol of an
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ideal gas from 22.4L and 1.00 atm to 10.5 L. Given that C P  R , calculate
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T1 , T2 , q , H , W. (Hint: q p  H )
(A) T1 = 285K, T2 = 607 K, q =- 3.01 kJ, H = -6.69 kJ, W = 1.21 kJ
(B) T1 = 285K, T2 = 607 K, q = 3.01 kJ, H = 3.01 kJ, W = 1.21 kJ
(C) T1 = 607K, T2 = 285 K, q = -3.01 kJ, H = 1.21 kJ, W = 6.69 kJ
(D) T1 = 607K, T2 = 285 K, q = -3.01 kJ, H = -3.01 kJ, W = 1.21 kJ #
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(14) For an adiabatic thermodynamic processes, the relation between T and V is given
as:
 1
 1
(A) T1 V1  T2 V2


(B) T1 V1  T2 V2
CP
CV
CP
CV
2 2
 1
#
2 2
T1V1  T V
 1
TV
(D) T1V1
(C)
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(15) An ideal monatomic gas initially at Po, Vo, and To undergoes an adiabatic compression
to volume
1
Vo . The final temperature is
10
(A) Tf 
1
To
10
 -1
1
(B) Tf    To
 10 
(C) Tf  10 1 To #
(D) Tf  10To
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With my best wishes
Dr. Ehteram A. Noor
Associate Professor
of
Physical Chemistry
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