Chapter 25 review

    Vocabulary
    Match each word to the sentence where it best fits.
      Section 25.1

      thermodynamics zeroth law of thermodynamics
      first law of thermodynamics second law of thermodynamics
      third law of thermodynamics entropy
      reversibility 
      1. No temperature exists below absolute zero, which is a consequence of the _______.

      2. That no heat will flow between two objects at the same temperature is a consequence of the _______.

      3. Heat and its transformation to and from mechanical energy is the subject of _______.

      4. If a thermodynamic process has the property of _______, then it can run forward and backward to return to its original state.

      5. The _______ of a system is a measure of the thermal energy that is not available to do work.

      6. A consequence of the _______ is that no heat can flow from a colder object to a warmer object unless work is done on them.

      7. The change in energy of a system equals the heat added to it plus the work done on it as defined by the _______.

      Section 25.2

      heat engine PV diagram
      isothermal process adiabatic process
      Carnot cycle Carnot efficiency
      refrigerator 
      1. A/An _______ is a four-stage process of an idealized heat engine.

      2. The area subtended by a thermodynamical process on a/an _______ is equal to the work done on the system.

      3. A system that can convert thermal energy into mechanical energy is a/an _______.

      4. A/An _______ uses a reverse Carnot cycle to extract heat from a colder object by doing work.

      1. The _______ illustrates that no real-world heat engine can convert all of the input heat into output work.

      2. Changes in pressure are inversely proportional to changes in volume at constant temperature in a/an _______.

      3. No heat is added or taken away from a system during a/an _______.

      Conceptual questions
        Section 25.1
        1. Which equation best represents the first law of thermodynamics?
          1. ΔS≥0
          2. PV=nRT
          3. W=−PΔV
          4. ΔE=Q+W


        2. Why don’t coffee cups ever reheat themselves?

        3. Selena has created a machine that converts heat into mechanical energy. She claims that her machine is so efficient that she can create 120 J of mechanical energy using only 90 J of heat. Do you believe Selena’s claim?

        4. Firnen claims that he can defy the law of entropy, as he can sort his bag of candies by color and separate the colors from one another. Has Firnen broken the second law of thermodynamics?

        5. You own a machine that becomes more efficient as you add more heat to it as a power source. Yet no matter how much heat you add to the machine, it never is more than 100% efficient. Explain this using the laws of thermodynamics.

        6. Describe how the first law of thermodynamics is related to the notion of energy conservation.

        7. If the volume of a gas changes by ΔV, choose the sentence that best describes what is meant by the negative sign in the following equation: W=−PΔV
          1. Pressure is directly proportional to the change in volume.
          2. Work is done on the gas.
          3. Work is done by the gas.
          4. The product of pressure and volume is given by the second law of thermodynamics.


        8. What quantity is used in physics to measure disorder?

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