Final answer:
Refrigerant recovery from systems using R-11 or R123 is required. For a fridge with a COP of 3.0 that requires 200 J of work, 600 J of heat is removed from the cold reservoir, and 800 J is expelled to the hot reservoir each cycle. Freon-12 remains a gas at room temperature.
Step-by-step explanation:
A student asked about the refrigerant recovery from an R-11 or R123 system. The answer to whether refrigerant should be recovered from systems using R-11 or R123 is Yes. Regarding thermodynamics applied to refrigerators and heat pumps, these systems follow the laws of thermodynamics which dictate energy interactions such as heat transfer and work done.
To address the second part of the question, for a refrigerator with a coefficient of performance of 3.0 that requires 200 J of work per cycle: The amount of heat removed from the cold reservoir per cycle can be calculated by multiplying the coefficient of performance (COP) by the work required, which gives us 3.0 * 200 J = 600 J. The heat discarded to the hot reservoir per cycle is the sum of the work done plus the heat removed from the cold reservoir. Hence, it is 200 J (work) + 600 J (heat removed) = 800 J per cycle.