Question 1

Use the following to answer question : 
-Heat is added to a substance at a constant rate. The substance starts as a solid and is melted; the liquid is heated and vaporized; finally, the vapor is heated at constant volume. This process is shown in the graph. The specific heat at constant volume of the vapor can be found by

Accepted Answer

A)  multiplying the length of B (in seconds) by the rate at which heat is added, and dividing by the mass of the substance. 
B)  multiplying the length of D (in seconds) by the rate at which heat is added, and dividing by the mass of the substance. 
C)  dividing the rate at which heat is added by the product of the slope of A and the mass of the substance. 
D)  dividing the rate at which heat is added by the product of the slope of C and the mass of the substance. 
E)  dividing the rate at which heat is added by the product of the slope of E and the mass of the substance.

Question 2

Use the following to answer question : 
-One mole of an ideal gas ($\gamma$ = 5/3) expands adiabatically and quasistatically from a pressure P1 = 3 atm and a temperature of 30ºC to a pressure P2 = 1 atm. How much work is done by the gas during this process? R = 8.314 J/mol·K = 8.206 L·atm/mol·K.

Accepted Answer

A)  50.3 kJ 
B)  63.5 kJ 
C)  95.9 kJ 
D)  131 kJ 
E)  158 kJ

Question 3

Use the following to answer question : 
-Heat is added to a substance at a constant rate. The substance starts as a solid and is melted; the liquid is heated and vaporized; finally, the vapor is heated. This process is shown in the graph. The specific heat of the solid can be found by

Accepted Answer

A)  multiplying the length of B (in seconds) by the rate at which heat is added, and dividing by the mass of the substance. 
B)  multiplying the length of D (in seconds) by the rate at which heat is added, and dividing by the mass of the substance. 
C)  dividing the rate at which heat is added by the product of the slope of A and the mass of the substance. 
D)  dividing the rate at which heat is added by the product of the slope of C and the mass of the substance. 
E)  dividing the rate at which heat is added by the product of the slope of E and the mass of the substance.

Question 4

If the heat capacities of both ice and steam are 0.5 cal/g · Cº, the quantity of heat required to change 1 g of ice at -10ºC to steam at 120ºC is approximately

Accepted Answer

A)  750 cal 
B)  735 cal 
C)  630 cal 
D)  620 cal 
E)  555 cal

Question 5

An ideal gas undergoes a cyclic expansion and compression along the path a$\to$b$\to$c$\to$a as shown above. The work done along c$\to$a of the cycle is the area

Accepted Answer

A)  shaded blue. 
B)  shaded yellow. 
C)  shaded blue and yellow. 
D)  negative of the area shaded blue. 
E)  negative of the area shaded yellow.

Question 6

A 1.0-kg piece of marble at 100ºC is dropped into 2.5 kg of water at 1.0ºC and the resulting temperature is 7.0ºC. The specific heat of the marble is approximately

Accepted Answer

A)  0.16 kcal/kg · Cº 
B)  0.75 kcal/kg · Cº 
C)  0.61 kcal/kg · Cº 
D)  0.30 kcal/kg · Cº 
E)  0.26 kcal/kg · Cº

Question 7

Use the following to answer question : 
-An ideal gas initially at 100ºC and pressure P1 = 250 kPa occupies a volume V1 = 4.5 L. It undergoes a quasistatic, isothermal expansion until its pressure is reduced to 150 kPa. How much does the internal energy of the gas change during this process? R = 8.314 J/mol·K = 8.206 L·atm/mol·K.

Accepted Answer

A)  116 J 
B)  320 J 
C)  575 J 
D)  640 J 
E)  The internal energy does not change during this process.

Question 8

The work done by a gas on a piston can be obtained from the graph, provided the abscissa represents the

Accepted Answer

A)  internal energy. 
B)  temperature. 
C)  density. 
D)  volume. 
E)  time.

Question 9

During a certain thermodynamic process, 418 J of work are done on a system and 214 cal of heat are transferred to the system. The change in internal energy during the process is

Accepted Answer

A)  314 cal 
B)  114 cal 
C)  468 cal 
D)  368 cal 
E)  632 cal

Question 10

The diagram above show the state of an ideal gas going from (V1,P1) to a final state. Which path best represents adiabatic expansion?

Accepted Answer

A)  1 
B)  2 
C)  3 
D)  4 
E)  none of the paths

Question 11

A container contains a 200 mL of 100% proof alcohol (i.e., it has 50% ethyl alcohol and 50% water by volume) at 20S1U1P1$\circ$S1S1P0C. How much heat is needed to bring the mixture to the boiling point of the alcohol? (assume that the specific heat in the 100% proof can be treated as due to the alcohol and water separately, and the density, boiling point and specific heat of alcohol are 0.81 g/cm3, 78S1U1P1$\circ$S1S1P0C, and 2.4 J/(g.CS1U1P1$\circ$S1S1P0), respectively)

Accepted Answer

A)  32650 J 
B)  35525 J 
C)  11136 J 
D)  17400 J 
E)  48557 J

Question 12

The specific heat of a substance is a measure of

Accepted Answer

A)  energy needed to change the kinetic energies of atoms and/or molecules and/or electrons by a temperature increment. 
B)  total energy in the substance for a given temperature change. 
C)  energy needed to vaporize/liquefy the substance. 
D)  energy needed to liquefy/solidify the substance. 
E)  none of the above

Question 13

In a certain thermodynamic process, 1000 cal of heat are added to a gas confined in a cylinder. At the same time, 1000 J of work are done by the gas as it expands. The increase in internal energy of the gas is

Accepted Answer

A)  zero 
B)  3186 J 
C)  -239 J 
D)  5186 J 
E)  1239 J

Question 14

Use the following to answer question : 
-An ideal gas initially at 50ºC and pressure P1 = 100 kPa occupies a volume V1 = 3 L. It undergoes a quasistatic, isothermal expansion until its pressure is reduced to 50 kPa. How much heat enters the gas during this process? R = 8.314 J/mol·K = 8.206 L·atm/mol·K.

Accepted Answer

A)  116 J 
B)  208 J 
C)  256 J 
D)  304 J 
E)  416 J

Question 15

A system has a heat capacity of 100 J. This means

Accepted Answer

A)  it is possible to extract the 100 J of heat and convert it to work. 
B)  it is possible to transfer the 100 J of heat to the environment. 
C)  some of the heat capacity can be converted to work. 
D)  some of the heat capacity can be transferred to another system if there is a temperature difference. 
E)  (
C)  and (
D)

Question 16

A reversible heat engine has the PV graph shown. The net work performed in one cycle is approximately

Accepted Answer

A)  zero 
B)  2.0 kJ 
C)  4.2 kJ 
D)  5.5 kJ 
E)  10 kJ

Question 17

An ideal monatomic gas has a molar heat capacity Cmp at constant pressure. What is the molar heat capacity at constant volume of an ideal diatomic gas?

Accepted Answer

A)  Cmp  
B)  Cmp + R 
C)  Cmp - R 
D)  Cmp + 3R/2 
E)  Cmp - 3R/2

Question 18

The first law of thermodynamics is most closely related to

Accepted Answer

A)  the definition of absolute zero. 
B)  the definition of an ideal gas. 
C)  the conservation of energy. 
D)  thermal expansion. 
E)  the conservation of momentum.

Question 19

Use the following to answer question : 
-The graph shows the temperature of a 1.0-g sample of material as heat is added to it. The material is initially a solid at 10ºC. The pressure remains constant, and there is no chemical change. The heat of fusion of the material is

Accepted Answer

A)  10 cal/g 
B)  50 cal/g 
C)  30 cal/g 
D)  90 cal/g 
E)  None of these is correct.

Question 20

For most metals, the heat capacity goes as C = $\gamma$T + AT3 at low temperatures (~ 100 K), whereas insulators only has the T3 term. Both $\gamma$ and A are constants. The two terms in the expression for C suggests

Accepted Answer

A)  there are at least two degrees of freedom in metals. 
B)  there are two independent mechanisms for heat to be absorbed or released in metals. 
C)  that there are two kinds of heat that are absorbed by metals. 
D)  that thermal energy is transferred to metals differently than insulators. 
E)  nothing. It just happens that way.

Exam 18: Heat and the First Law of Thermodynamics

Use the following to answer question : -Heat is added to a substance at a constant rate. The substance starts as a solid and is melted; the liquid is heated and vaporized; finally, the vapor is heated. This process is shown in the graph. The specific heat of the solid can be found by

If the heat capacities of both ice and steam are 0.5 cal/g · Cº, the quantity of heat required to change 1 g of ice at -10ºC to steam at 120ºC is approximately

A 1.0-kg piece of marble at 100ºC is dropped into 2.5 kg of water at 1.0ºC and the resulting temperature is 7.0ºC. The specific heat of the marble is approximately

The work done by a gas on a piston can be obtained from the graph, provided the abscissa represents the

During a certain thermodynamic process, 418 J of work are done on a system and 214 cal of heat are transferred to the system. The change in internal energy during the process is

The diagram above show the state of an ideal gas going from (V₁,P₁) to a final state. Which path best represents adiabatic expansion?

The specific heat of a substance is a measure of

In a certain thermodynamic process, 1000 cal of heat are added to a gas confined in a cylinder. At the same time, 1000 J of work are done by the gas as it expands. The increase in internal energy of the gas is

A system has a heat capacity of 100 J. This means

A reversible heat engine has the PV graph shown. The net work performed in one cycle is approximately

An ideal monatomic gas has a molar heat capacity C_mp at constant pressure. What is the molar heat capacity at constant volume of an ideal diatomic gas?

The first law of thermodynamics is most closely related to

Use the following to answer question : -The graph shows the temperature of a 1.0-g sample of material as heat is added to it. The material is initially a solid at 10ºC. The pressure remains constant, and there is no chemical change. The heat of fusion of the material is

For most metals, the heat capacity goes as C = $\gamma$ T + AT³ at low temperatures (~ 100 K) , whereas insulators only has the T³ term. Both $\gamma$ and A are constants. The two terms in the expression for C suggests

Exam 18: Heat and the First Law of Thermodynamics

Use the following to answer question : -Heat is added to a substance at a constant rate. The substance starts as a solid and is melted; the liquid is heated and vaporized; finally, the vapor is heated. This process is shown in the graph. The specific heat of the solid can be found by

If the heat capacities of both ice and steam are 0.5 cal/g · Cº, the quantity of heat required to change 1 g of ice at -10ºC to steam at 120ºC is approximately

An ideal gas undergoes a cyclic expansion and compression along the path a →\to→ b →\to→ c →\to→ a as shown above. The work done along c →\to→ a of the cycle is the area

A 1.0-kg piece of marble at 100ºC is dropped into 2.5 kg of water at 1.0ºC and the resulting temperature is 7.0ºC. The specific heat of the marble is approximately

The work done by a gas on a piston can be obtained from the graph, provided the abscissa represents the

During a certain thermodynamic process, 418 J of work are done on a system and 214 cal of heat are transferred to the system. The change in internal energy during the process is

The diagram above show the state of an ideal gas going from (V1,P1) to a final state. Which path best represents adiabatic expansion?

The specific heat of a substance is a measure of

In a certain thermodynamic process, 1000 cal of heat are added to a gas confined in a cylinder. At the same time, 1000 J of work are done by the gas as it expands. The increase in internal energy of the gas is

A system has a heat capacity of 100 J. This means

A reversible heat engine has the PV graph shown. The net work performed in one cycle is approximately

An ideal monatomic gas has a molar heat capacity Cmp at constant pressure. What is the molar heat capacity at constant volume of an ideal diatomic gas?

The first law of thermodynamics is most closely related to

Use the following to answer question : -The graph shows the temperature of a 1.0-g sample of material as heat is added to it. The material is initially a solid at 10ºC. The pressure remains constant, and there is no chemical change. The heat of fusion of the material is

For most metals, the heat capacity goes as C = γ\gammaγ T + AT3 at low temperatures (~ 100 K) , whereas insulators only has the T3 term. Both γ\gammaγ and A are constants. The two terms in the expression for C suggests

The diagram above show the state of an ideal gas going from (V₁,P₁) to a final state. Which path best represents adiabatic expansion?

An ideal monatomic gas has a molar heat capacity C_mp at constant pressure. What is the molar heat capacity at constant volume of an ideal diatomic gas?

For most metals, the heat capacity goes as C = $\gamma$ T + AT³ at low temperatures (~ 100 K) , whereas insulators only has the T³ term. Both $\gamma$ and A are constants. The two terms in the expression for C suggests