Chemical Thermodynamics

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, R= 8.314 J mol–1 K–1
Section: / 1 atm = 1.01325×105 Pa, 1atm = 760 mmHg
1atm = 76 cmHg

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.

______

(2)Which of the following is not an intensive property?

(A)enthalpy #

(B)Density

(C)Temperature

(D)Specific volume

______

(3)Which of the following is an extensive property?

(A)Entropy

(B)Enthalpy

(C)Volume

(D)All of the above.#

______

(4)In which of the following processes, dT =0?

(A)Adiabatic process

(B)Isobaric process

(C)Isothermal process #

(D)Isochoric process

______

(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.

(D)50 J of work done on the process; 50 J of heat exchange.

______

(6)If the systems A and B are in thermal equilibrium with system C, then system A is also in thermalequilibrium with system B. In thermodynamics, this statement is known as

(A)1st law

(B)2nd law

(D)zeroeth law#

______

(7)The work done during the free expansion of an ideal gas is equal to

(A)Pext

(B)dV

(C)dE

(D)zero#

(8)The work done during isothermalirreversible change will be given by

(A)#

(B)

(C)

(D)Zero

______

(9)Two litres of an ideal gas at a pressure of 10 atm expands isothermally againstspace until its totalvolume becomes 100 litres.The amount of heat absorbed in the expansion is

(A)2.303 J

(B)100 J

(C)Zero#

(D)90 J

______

(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.

(D)All.

______

(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

______

(12)A gas is allowed to expand from a volume of 1.0 L to 10.1 L against anexternal pressure of 0.50 atm. If the gas absorbs 250 J of heat from the surroundings, what are thevalues of q, w, and respectively?

(A) 250 J, -461 J, -211 J#

(B)-250 J, -461 J, -711 J

(D) 250 J, -4.55 J, 245 J

______

(13)Consider an isobaric compression (cooling from T1 to T2) of 0.450 mol of an ideal gas from 22.4L and1.00 atm to 10.5 L. Given that , calculate , , , W. (Hint: )

(A)T1 = 285K, T2 = 607 K, q =- 3.01 kJ, = -6.69 kJ, W = 1.21 kJ

(B)T1 = 285K, T2 = 607 K, q = 3.01 kJ, = 3.01 kJ, W = 1.21 kJ

(C)T1 = 607K, T2 = 285 K, q = -3.01 kJ,= 1.21 kJ, W = 6.69 kJ

(D)T1 = 607K, T2 = 285 K, q = -3.01 kJ, = -3.01 kJ, W = 1.21 kJ#

(14)For an adiabatic thermodynamic processes, the relation between T and V is given as:

(A)

(B)

(C)

(D)#

______

(15)An ideal monatomic gas initially at Po, Vo, and To undergoes an adiabatic compression to volume . The finaltemperature is

(A)

(B)

(C)#

(D)

______

With my best wishes

Dr. Ehteram A. Noor

Associate Professor

Physical Chemistry