Instructions:

This is a closed book exam. You may use your own calculator (but may not share calculators) as well as the attached equation sheet. This exam is designed to take a class period (50 minutes), but additional time will be provided.

This exam comes in two parts, conceptual and quantitative. For conceptual problems, credit will depend only on your chosen answers, with no partial credit. For quantitative problems, you must show all work -- including drawings and free body diagrams -- to receive credit. Cross out extraneous work, and circle your final answer.

You are reminded of your obligation to observe the Emory Honor Code in taking this exam.

Summary:

Your NAME________________________

Conceptual Questions (70 points):

Quantitative Problems (30 points):

Your SCORE____(100)

Conceptual Questions (5 points each)

Questions 1 -- 6 refer to the following situation:

Mystery substance X has the following thermodynamic data:

1. How much heat is required to heat 1 kg of liquid X from 10 C to 210 C?
   1. 0.500 kcal
   2. 40 kcal
   3. 100 kcal
   4. 150 kcal
   5. 200 kcal
2. How much heat is required to boil 1 kg of liquid X at 210 C?
   1. 0.500 kcal
   2. 40 kcal
   3. 100 kcal
   4. 150 kcal
   5. 200 kcal
3. What is the fractional change in its volume, when liquid X decreases in temperature by 10 C?
   1. Liquid X's volume increases by 4%.
   2. Liquid X's volume increases by 0.4%.
   3. Liquid X's volume remains the same.
   4. Liquid X's volume decreases by 4%.
   5. Liquid X's volume decreases by 0.4%.
4. A sample of liquid X at 80 C sits in a 0 C room, and cools by radiation only. It loses energy at the rate 1 W. If the room temperature were increased to 40 C, at what rate would the 80 C sample of liquid X now lose energy?
   1. 0.06 W
   2. 0.5 W
   3. 0.6 W
   4. 1 W
   5. 2 W

   
   

   Questions 5 and 6 pertain to the following specific process undergone by substance X:

   
   

   1 kg of substance X is heated from an initial temperature of -10 C to a final state which is a mixture of 0.3 kg of liquid X and 0.70 kg of gas X.

   
   

5. Which one of the following is an accurate qualitative depiction of the sample's evolution in pressure and temperature?

   

6. Which one of the following is an accurate qualitative depiction of the sample's temperature variation as heat is added?

   

   
   
   Questions 7 through 12 pertain to the situation described below:

   An ideal monatomic gas originally in state A at temperature 27 C can be taken to state B at temperature via any of the thermodynamic processes shown.

   
   For these questions you may choose to use the ideal gas constants , though they are not strictly necessary.

7. Which of the following is an accurate ordering of the amount of work done (W) by the gas in each of these processes?
   1. 
   2. 
   3. 
   4. 
   5. This cannot be determined from the information given.
8. How much work is done by the gas in process I? (Note the conversion factor 1 atm l = 100 J.)
   1. 900 J
   2. 600 J
   3. none
   4. -600 J
   5. -900 J

9. What is the temperature of the gas in state B?
   1. -123 C
   2. 27 C
   3. 54 C
   4. 327 C
   5. This cannot be determined from the information given.
10. In process III, the gas expands from state A to state C isothermally, doing 480 J of work. What is the change in entropy ( ) for the gas during the isothermal process AC?
    1. 18 J/K
    2. 1.6 J/K
    3. 0 J/K
    4. -1.6 J/K
    5. -18 J/K

    
    

    Questions 11 and 12 both refer to process IV, where the gas expands from state A to state D adiabatically, with C.

    
    

11. What is the change in internal energy of the gas during the adiabatic process AD?
    1. -225 J
    2. -150 J
    3. 0 J
    4. 150 J
    5. 225 J
12. How much work does the gas do in process IV (for the entire process, from A to D to B)?
    1. 300 J
    2. 225 J
    3. 150 J
    4. none
    5. -150 J

    Questions 13 and 14 pertain to the following situation:

    
    

    A heat engine operates between a hot reservoir at 1500 K and a cold reservoir at 500 K. J of heat is removed from the hot reservoir and J of work is performed.

13. What is the actual efficiency of this engine?
    1. 0.15
    2. 0.34
    3. 0.50
    4. 0.67
    5. 0.81
14. What is the ideal (Carnot) efficiency of this engine?
    1. 0.15
    2. 0.34
    3. 0.50
    4. 0.67
    5. 0.81

Quantitative Problems (Point Value as Marked)

1. (30 points)
   
   A 350 g copper ingot at C is placed in a calorimeter with 420 g of water at C. Specific heats for copper, water, and ice are

   

   while the heat of fusion for water is .

   1. How much heat would be required to raise the temperature of the copper ingot to C?
   2. What is the final state of the system? Give both the final temperature, and the masses of water and/or ice present.

   
   
   
   
   
   
   

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