Entropy of a system can never decrease

[shenwei1988]

heat! so hard.

true or false


1.The entropy of a system can never decrease

2.All Carnot engines are reversible

3.It is impossible have a net transfer of heat from a cold reservoir to a warm reservoir

4.A refrigerator lowers the entropy of the volume inside

5.If the temperature of the cold reservoir increases with the temperature of the hot reservoir unchanged, the efficiency of a Carnot engine will increase

6.Adiabatic expansion will lower the temperature of a gas

7.Any process that includes adding heat to an ideal gas will increase the entropy of the gas

8.All Carnot engines are more efficient than all real engines

 

[robertm]

No one will do your work for you.

If you have a genuine interest in knowing the answer to these questions you must show that you have actually thought about them, also ask them one or two at a time with effort given on each. Good luck.

 

[Moetasim]

1. True. Entropy is a measure of the disorder or randomness in a system, and it tends to increase over time. This is known as the second law of thermodynamics.

2. True. All Carnot engines operate at maximum theoretical efficiency and are reversible, meaning they can run in both directions.

3. True. Heat naturally flows from a warmer object to a cooler object, so it would be impossible for heat to flow in the opposite direction without external work being done.

4. False. A refrigerator actually increases the entropy of the volume inside, as it transfers heat from a colder area to a warmer area.

5. False. The efficiency of a Carnot engine is dependent on the temperature difference between the hot and cold reservoirs, not just the temperature of the cold reservoir.

6. True. Adiabatic expansion involves no heat transfer, so the temperature of the gas will decrease as the volume increases.

7. True. Adding heat to a gas increases its internal energy and therefore its disorder, leading to an increase in entropy.

8. True. Real engines have various inefficiencies and losses, so they cannot achieve the maximum theoretical efficiency of a Carnot engine.