A 4 mole ideal gas system undergoes an adiabatic process where it expands and does 20 J of work on its environment. How much heat is received by the system?

1
A 4 mole ideal gas system undergoes an adiabatic
process where it expands and does 20 J of work on
its environment. How much heat is received by the
system?

1. -20 J
2. zero
3. 5 J
4. 20 J

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
2
A 5 mole ideal gas system undergoes an adiabatic
free expansion, going from an initial volume of
10 liters to a final volume of 20 liters. How
much work is done by the system during this
adiabatic free expansion?

1. -50 J
2. -10 J
3. zero
4. 50 J

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
3
A heat engine receives 6000 J of heat from its
combustion process and loses 4000 J through the
exhaust and friction. What is its efficiency?

1. 33
2. 40
3. 67
4. 73

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
4
If a heat engine has an efficiency of 30 and its
power output is 600 W, what is the rate of heat
input from the combustion phase?

1. 1800 W
2. 2400 W
3. 2000 W
4. 3000 W

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
5
A steam turbine operates at a boiler temperature
of 450 K and an exhaust temperature of 300 K.
What is the maximum theoretical efficiency of
this system?

1. 24
2. 50
3. 33
4. 67

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
6
A 4 mole ideal gas system undergoes an adiabatic
process where it expands and does 20 J of work on
its environment. What is its change in internal
energy?

1. -20 J
2. -5 J
3. zero
4. 20 J

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
7
The maximum theoretical thermodynamic efficiency
of a heat engine operating between hot and cold
reservoirs is a function of which of the
following?

1. hot reservoir temperature only
2. cold reservoir temperature only
3. both hot and cold reservoir temperatures
4. none of these choices are valid

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
8
During an isobaric process which one of the
following does not change?

1. volume
2. temperature
3. internal energy
4. pressure

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
9
A 2 mole ideal gas system is maintained at a
constant volume of 4 liters if 100 J of heat is
added, what is the work done by the system?

1. zero
2. 5.0 J
3. 6.7 J
4. 20 J

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
10
A 2 mole ideal gas system is maintained at a
constant volume of 4 liters if 100 J of heat is
added, what is the change in internal energy of
the system?

1. zero
2. 50 J
3. 67 J
4. 100 J

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
11
According to the second law of thermodynamics,
which of the following applies to the heat
received from a high temperature reservoir by a
heat engine operating in a complete cycle?

1. must be completely converted to work
2. equals the entropy increase
3. converted completely into internal energy
4. cannot be completely converted to work

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
12
An adiabatic free expansion refers to the fact
that

1. no heat is transferred between a system and its
   surroundings.
2. the pressure remains constant.
3. the temperature remains constant.
4. the volume remains constant.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
13
According to the first law of thermodynamics, the
difference in heat gained by a system and the
work done by that same system is equivalent to
which of the following?

1. entropy change
2. internal energy change
3. temperature change
4. specific heat

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
14
If an ideal gas does positive work on its
surroundings, then which one of the following
choices may be assumed with regard to the gas?

1. temperature increases
2. volume increases
3. pressure increases
4. internal energy decreases

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
15
In an isovolumetric process by an ideal gas, the
system's heat gain is equivalent to a change in
which one of the following?

1. temperature
2. volume
3. pressure
4. internal energy

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
16
A one kilogram chunk of ice at 0C melts,
absorbing 80,000 cal of heat in the process.
Which of the following best describes what
happens to this system?

1. increased entropy
2. lost entropy
3. entropy maintained constant
4. work converted to energy

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
17
According to the second law of thermodynamics,
for any process that may occur within an isolated
system, which of the following choices applies?

1. entropy remains constant
2. entropy increases
3. entropy decreases
4. none of these choices applies

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
18
Which of the following choices is an appropriate
unit for measuring entropy changes?

1. joule-K
2. newton-K
3. joule/s
4. joule/K

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
19
An electrical power plant manages to send 88 of
the heat produced in the burning of fossil fuel
into the water-to-steam conversion. Of the heat
carried by the steam, 40 is converted to the
mechanical energy of the spinning turbine. Which
of the following choices best describes the
overall efficiency of the heat-to-work conversion
in the plant (as a percentage)?

1. greater than 88
2. 64
3. less than 40
4. 40

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
20
If one could observe the individual atoms making
up a piece of matter and note that during a
process of change their motion somehow became
more orderly, then one may assume which of the
following in regard to the system?

1. increases in entropy
2. decreases in entropy
3. gains in thermal energy
4. positive work done on

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
21
Which of the following choices best corresponds
to what is required by the second law of
thermodynamics for any process taking place in an
isolated system?

1. entropy decreases
2. entropy remains constant
3. entropy increases
4. entropy equals work done

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
22
An ideal gas is maintained at a constant pressure
of 70,000 N/m2 during an isobaric process while
its volume decreases by 0.2 m3 . What work is
done by the system on its environment?

1. 14,000 J
2. 350,000 J
3. -14,000 J
4. -35,000 J

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
23
In an isothermal process for an ideal gas system
(where the internal energy doesn't change), which
of the following choices best corresponds to the
value of the work done by the system?

1. its heat intake
2. twice its heat intake
3. the negative of its heat intake
4. twice the negative of its heat intake

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
24
A system which receives 70 J of heat from its
environment and does 20 J of work will have what
net change in its internal energy?

1. 90 J
2. 50 J
3. zero
4. -70 J

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
25
A heat engine performs 2000 J of work while
rejecting 5000 J of heat to the cold-temperature
reservoir. What is the efficiency of the engine?

1. 71.4
2. 60.0
3. 40.0
4. 28.6

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
26
A heat engine operating between a pair of hot and
cold reservoirs with respective temperatures of
500 K and 200 K will have what maximum efficiency?

1. 60
2. 50
3. 40
4. 30

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
27
An 800 MW electric power plant has an efficiency
of 30. It loses its waste heat in large cooling
towers. Approximately how much waste heat (in MJ)
is discharged to the atmosphere per second?

1. 1200 MJ
2. 1800 MJ
3. 800 MJ
4. 560 MJ

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
28
A gasoline engine with an efficiency of 30
operates between a high temperature T1 and a low
temperature T2 320 K. If this engine operates
with Carnot efficiency, what is the high-side
temperature T1 ?

1. 1066 K
2. 868 K
3. 614 K
4. 457 K

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
29
A Florida home is kept cool in the summer by an
air conditioner. The outside temperature is 36C
and the inside of the home is kept at 18C. If 50
MJ of heat is removed from the house per hour,
what is the minimum power that must be provided
to run the air conditioner?

1. 214 W
2. 430 W
3. 860 W
4. 1720 W

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
30
The surface of the sun is approximately 5700 K
and the temperature of the Earth's surface is
about 290 K. What total entropy change occurs
when 1000 J of heat energy is transferred from
the sun to the Earth?

1. 2.89 J/K
2. 3.27 J/K
3. 3.62 J/K
4. 3.97 J/K

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
31
The efficiency of a Carnot engine operating
between 100C and 0C is most nearly

1. 7
2. 15
3. 27
4. 51

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
32
What is the coefficient of performance of a
refrigerator that operates with Carnot efficiency
between temperatures -7C and 31C?

1. 7.0
2. 9.1
3. 10.0
4. 13.2

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
33
How much work is required, using an ideal Carnot
refrigerator, to remove 1 J of heat energy from
helium gas at 4 K and reject this heat to a room
temperature (293 K) environment?

1. 13.9 J
2. 26.7 J
3. 52.6 J
4. 72.3 J

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
34
On a cold day, a heat pump is used to extract
heat energy from the outside air at -5C and
bring it into the 20C house. What minimum
amount of work must be done to bring 1000 J of
heat energy into the house?

1. 40.0 J
2. 60.0 J
3. 85.3 J
4. 100.1 J

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
35
Suppose a power plant uses a Carnot engine to
generate electricity, using the atmosphere at 300
K as the low temperature reservoir. Suppose the
power plant produces 1 x 106 J of electricity
with the hot reservoir at 500 K during one day
and then produces 1 x 106 J of electricity with
the hot reservoir at 600 K during the second
day. On these two days the thermal pollution was

1. greatest on the first day
2. greatest on the second day
3. the same on both days
4. zero on both days

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
36
A bottle containing an ideal gas has a volume of
2m3 and a pressure of 1 x 105 N/m2 at a
temperature of 300 K. The bottle is placed
against a metal block that is maintained at 900
K and the gas expands as the pressure remains
constant until the temperature of the gas reaches
900 K. The change in internal energy of the gas
is 6 x 105 J. How much heat did the gas absorb?

1. 0
2. 4 x 105 J
3. 6 x 105 J
4. 10 x 105 J

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
37
A bottle containing an ideal gas has a volume of
2m3 and a pressure of 1 x 105 N/m2 at a
temperature of 300 K. The bottle is placed
against a metal block that is maintained at 900
K and the gas expands as the pressure remains
constant until the temperature of the gas reaches
900 K. The change in internal energy of the gas
is 6 x 10 5 J. What is the change in entropy of
the block?

1. 0
2. 670 J/K
3. -440 J/K
4. -1100 J/K

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
38
When gasoline is burned, it gives off 46,000
J/gram of heat energy. If an automobile uses 13.0
kg of gasoline per hour with an efficiency of
21, what is the average horsepower output of the
engine? (1 HP 746 W)

1. 46.76 HP
2. 108.7 HP
3. 67.2 HP
4. 33.6 HP

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
39
An ideal gas at pressure, volume, and
temperature, P0 , V0 , and T0 , respectively, is
heated to point A, allowed to expand to point B
at constant temperature 2T0 , and then returned
to the original condition. The internal energy
increases by 3P0V0 /2 going from point B to point
T0 . In going around this cycle once, which
quantity equals zero?

1. The total change in internal energy of the gas.
2. The total work done by the gas.
3. The total heat added to the gas.
4. All three are zero.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
40
An ideal gas at pressure, volume, and
temperature, P0 , V0 , and T0 , respectively, is
heated to point A, allowed to expand to point B
at constant temperature 2T0 , and then returned
to the original condition. The internal energy
increases by 3P0V0 /2 going from point B to point
T0 . How much heat left the gas from point B to
point T0 ?

1. 0
2. POVO/2
3. 3 POVO/2
4. 5 POVO/2

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
41
For which system is heat usually transferred from
the cooler part of the system to warmer material?

1. a stove as it heats up water
2. a refrigerator that is running
3. an electric fan that is running
4. none of these, because it is impossible to
   transfer heat in this manner

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
42
An ideal gas at pressure, volume, and
temperature, P0 , V0 , and T0 , respectively, is
heated to point A, allowed to expand to point B
at constant temperature 2T0 , and then returned
to the original condition. The internal energy
increases by 3P0V0 /2 going from point B to point
T0 . How much heat left the gas from point T0 to
point A?

1. 0
2. POVO/2
3. 3 POVO/2
4. 5 POVO/2

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
43
Heat is applied to an ice-water mixture to melt
the ice. In this process

1. work is done by the ice-water mixture.
2. the temperature increases.
3. the internal energy increases.
4. all of these will occur.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
44
What is the work done by the gas as it expands
from pressure P1 and volume V1 to pressure P2
and volume V2 along the indicated straight line?

1. (P1 P2) (V2 V1) /2
2. (P1 P2) (V2 V1)
3. (P1 - P2) (V2 V1) /2
4. (P1 - P2) (V2 V1)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
45
As the ideal gas expands from pressure P1 and
volume V1 to pressure P2 and volume V2 along
the indicated straight line, it is possible that

1. the temperature stays constant.
2. the internal energy decreases.
3. the gas is changing state.
4. all of these are impossible for this particular
   graph.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
46
Which of the following increases the internal
energy of a solid metal rod?

1. Raising it to a greater height.
2. Throwing it through the air.
3. Having the rod conduct heat.
4. Having the rod absorb heat.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
47
An electrical generating plant operates at a
boiler temperature of 220C and exhausts the
unused heat into a nearby river at 19C. If the
generating plant has a power output of 800
megawatts and if the actual efficiency is 3/4ths
the theoretical efficiency, how much heat per
second must be delivered to the boiler? (0C
273 K)

1. 5200 megawatts
2. 1810 megawatts
3. 3620 megawatts
4. 2600 megawatts

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
48
During each cycle of operation a refrigerator
absorbs 55 cal from the freezer compartment and
expels 85 cal to the room. How much work input is
required to operate the system? (1 cal 4.186 J)

1. 125 J
2. 146 J
3. 356 J
4. 565 J

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
49
During each cycle of operation a refrigerator
absorbs 55 cal from the freezer compartment and
expels 85 cal to the room. If one cycle occurs
every 10 s, how many minutes will it take to
freeze 500 gm of water, initially at 0C? (Lv
80 cal/gm)

1. 800 min
2. 4400 min
3. 121 min
4. 60 min

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
50
An electrical generating plant operates at a
boiler temperature of 220C and exhausts the
unused heat into a nearby river at 18C. What is
the maximum theoretical efficiency of the plant?
(0C 273 K)

1. 61
2. 32
3. 21
4. 41

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
51
On a winter day an ideal heat pump operates with
an outdoor temperature of 5C while indoors it is
22C. What is the theoretical coefficient of
performance of this heat pump? (0C 273 K)

1. 3
2. 7
3. 17
4. 21

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
52
A 1 kg block of ice at 0C and 1 ATM melts
completely to water. What is its change in
entropy? (For ice, Lf 3.34 x 105 J/kg)

1. 3340.0 J/K
2. 2168.7 J/K
3. 613.6 J/K
4. 1223.4 J/K

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
53
One kilogram of water at the 1 ATM boiling point
(100 C) is heated until all the water vaporizes.
What is its change in entropy? (For water, Lvap
2.26 x 106 J/kg)

1. 12118 J/K
2. 6059 J/K
3. 3030 J/K
4. 1223 J/K

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
54
What is the change in entropy (DS) when one mole
of silver (108 g) is completely melted at 961C?
(The heat of fusion of silver is 8.82 x 104
J/kg.)

1. 5.53 J/K
2. 7.72 J/K
3. 9.91 J/K
4. 12.10 J/K

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
55
An avalanche of ice and snow of mass 1800 kg
slides a vertical distance of 160 meters down a
mountainside. If the temperature of the ice,
snow, mountain and surrounding air are all at
0C, what is the change in entropy of the
universe?

1. 31015 J/K
2. 10338 J/K
3. 3165 J/K
4. 1055 J/K

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50