Identify the following gas compression descriptions as adiabatic, isothermal or isobaric.

a. As the gas compresses, the internal energy ÄU, decreases when the temperature decreases; the work done on the gas is greater than the heat removed from the gas: ___________________

b. As the gas compresses, both ÄU and temperature of the gas increase as work is done on the gas; no heat is lost or gained by the gas during the process: _______________________

c. As the gas compresses, the heat removed from the gas is equal to the work done on the gas; ÄU is equal to zero and the temperature of the gas remains constant throughout the process: ________________________________

b. is adiabatic (no heat in or out)

c. is isothermal (constant T)

a. can be isobaric (compression as heat is removed to maintain constant P), but does not have to be.

a. This description corresponds to an adiabatic compression. In an adiabatic process, there is no heat transfer between the system and its surroundings. The decrease in temperature indicates a decrease in internal energy, and the fact that the work done on the gas is greater than the heat removed from the gas implies that the compression is adiabatic.

b. This description corresponds to an isentropic (also known as adiabatic) compression. In an isentropic process, there is no heat transfer between the system and its surroundings. The increase in both internal energy and temperature indicates that work is being done on the gas without any heat loss or gain.

c. This description corresponds to an isothermal compression. In an isothermal process, the temperature of the gas remains constant throughout the process. The fact that the heat removed from the gas is equal to the work done on the gas implies that the compression is isothermal. Additionally, the given information that the change in internal energy (ÄU) is equal to zero is consistent with an isothermal process, as there is no change in internal energy in such a process.