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During a thermodynamic process, the entropy of a certain system decreases by 1.0 J/K. What are some possible entropy changes that could have occurred within the system's surrounding environment?<--EndFragment-->
  1.Its entropy could have also decreased by 1.0 J/K.
  2.Its entropy could have remained constant.
  3.Its entropy could have increased by 2.5 J/K.
  4.All of these could have occurred.

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[Ques. 2] In a reversible cycle
  1.the change in the entropy of the system (measured over the whole cycle) is always zero.
  2.the change in the entropy of the system (measured over the whole cycle) may be zero, but it isn't necessarily always zero.
  3.The change in the entropy of the system (measured over the whole cycle) is always greater than zero.
  4.The change in the entropy of the system (measured over the whole cycle) is always less than zero.

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[Ques. 3] Which of the numbers 0.1, 1.0, and 2.0 represent possible values for the COP of a heat pump?
  1.0.1 only
  2.1.0 only
  3.2.0 only
  4.all of these.

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[Ques. 4] Assume that a closed system undergoes a reversible process that takes it from state A to a different state B. In which of these cases will the entropy of the system remain constant?<--EndFragment--> ea breeze is
  1.if the process is isothermal
  2.if the process is adiabatic
  3.if the process is isovolumetric
  4.The system's entropy will remain constant for all of these cases.

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[Ques. 5] You can choose between a heat pump and an electric heater to heat your house. If you assume that the electric heater is 100 efficient at turning electrical energy into heat, an electric heat pump of what coefficient of performance (COP) will result in the same cost of electricity for the same amount of heating? Assume that the motor that runs the heat pump is 100 efficient.
  1.0.25
  2.0.5
  3.1.0
  4.2.0

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[Ques. 6] If a car engine has a thermal efficiency of 50 and it does 500 J of work in one cycle, how much energy does it expel to the cold reservoir each cycle?
   
  1.250 J.
  2.500 J.
  3.750 J.
  4.1000 J.

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[Ques. 7] If a car engine has a thermal efficiency of 50 and it does 500 J of work in one cycle, how much energy input does it require each cycle?
  1.250 J
  2.500 J
  3.750 J
  4.1000 J

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[Ques. 8] In an isovolumetric process,
  1.there is never any transfer of energy by heat between the system and its surroundings.
  2.the pressure remains constant.
  3.the temperature remains constant.
  4.there is no work done on or by the system.

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[Ques. 9] A gas that expands adiabatically
  1.experiences no temperature change.
  2.has no work done on it and does no work.
  3.experiences no change in internal energy due to energy transfer by heat
  4.increases in temperature.

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[Ques. 10] Can the temperature of an ideal gas and the internal energy of an ideal gas increase with no energy transfer by heat?
  1.No, if there is no energy transfer by heat to an ideal gas, then the internal energy of the gas must stay constant and so must its temperature.
  2.No, although the internal energy of the ideal gas may increase with no energy transfer by heat, the temperature of the gas will not change.
  3.Yes, the temperature of an ideal gas and the internal energy of an ideal gas can increase with no energy transfer by heat.
  4.No, although the temperature of the ideal gas may increase with no energy transfer by heat, the internal energy will not change.

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I'm still confused, but thanks for answering correctly