A standard air conditioner involves a refrigerant that is typically now a fluorinated hydrocarbon, such as CH₂F₂. An air-conditioner refrigerant has the property that it readily vaporizes at atmospheric pressure and is easily compressed to its liquid phase under increased pressure. The operation of an air conditioner can be thought of as a closed system made up of the refrigerant going through the two stages shown here (the air circulation is not shown in this diagram).
During expansion, the liquid refrigerant is released into an expansion chamber at low pressure, where it vaporizes. The vapor then undergoes compression at high pressure back to its liquid phase in a compression chamber. (c) In a central air-conditioning system, one chamber is inside the home and the other is outside. Which chamber is where, and why?

Verified step by step guidance

Identify the two chambers involved in the air conditioning system: the expansion chamber and the compression chamber.

Understand the function of each chamber: the expansion chamber allows the refrigerant to vaporize, absorbing heat, while the compression chamber condenses the refrigerant, releasing heat.

Consider the purpose of each chamber in relation to the environment: the expansion chamber should be where cooling is needed, and the compression chamber should be where heat can be dissipated.

Determine the location of each chamber based on their functions: the expansion chamber should be inside the home to absorb heat and cool the air, while the compression chamber should be outside to release the absorbed heat into the environment.

Conclude that the expansion chamber is inside the home to provide cooling, and the compression chamber is outside to expel heat.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.

Video duration:

Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Phase Changes

Phase changes refer to the transitions between solid, liquid, and gas states of matter. In the context of air conditioning, the refrigerant undergoes phase changes from liquid to gas during expansion and from gas to liquid during compression. Understanding these transitions is crucial for grasping how refrigerants absorb and release heat, which is fundamental to the cooling process.

Thermodynamics

Thermodynamics is the study of energy transfer and the laws governing heat and work. In air conditioning systems, the principles of thermodynamics explain how energy is conserved and transformed as the refrigerant circulates. The concepts of pressure, temperature, and enthalpy are essential for understanding how the refrigerant operates within the system, particularly during the compression and expansion processes.

Closed System

A closed system is a physical system that does not exchange matter with its surroundings but can exchange energy. In the case of an air conditioner, the refrigerant circulates within a closed loop, allowing it to absorb heat from the indoor environment and release it outside. Recognizing the closed system nature of the air conditioning process helps in understanding how the refrigerant's properties are utilized to achieve efficient cooling.

Recommended video:

Guided course

02:06

Entropy of the System

Related Practice

Textbook Question

For each of the following processes, indicate whether the signs of ΔS and ΔH are expected to be positive, negative, or about zero. (a) A solid sublimes. (b) The temperature of a sample of Co(s) is lowered from 60 °C to 25 °C. (c) Ethyl alcohol evaporates from a beaker. (d) A diatomic molecule dissociates into atoms. (e) A piece of charcoal is combusted to form CO₂(g) and H₂O(g).

Textbook Question

The reaction 2 Mg(s) + O₂(g) ⟶ 2 MgO(s) is highly spontaneous. A classmate calculates the entropy change for this reaction and obtains a large negative value for ΔS°. Did your classmate make a mistake in the calculation? Explain.

Textbook Question

Consider a system that consists of two standard playing dice, with the state of the system defined by the sum of the values shown on the top faces. (f) Calculate the absolute entropy of the two-dice system.

Textbook Question

A standard air conditioner involves a refrigerant that is typically now a fluorinated hydrocarbon, such as CH₂F₂. An air-conditioner refrigerant has the property that it readily vaporizes at atmospheric pressure and is easily compressed to its liquid phase under increased pressure. The operation of an air conditioner can be thought of as a closed system made up of the refrigerant going through the two stages shown here (the air circulation is not shown in this diagram).

During expansion, the liquid refrigerant is released into an expansion chamber at low pressure, where it vaporizes. The vapor then undergoes compression at high pressure back to its liquid phase in a compression chamber. (e) Suppose that a house and its exterior are both initially at 31 °C. Some time after the air conditioner is turned on, the house is cooled to 24 °C. Is this process spontaneous or nonspontaneous?

views

Textbook Question

Trouton’s rule states that for many liquids at their normal boiling points, the standard molar entropy of vaporization is about 88 J/mol‐K. b. Look up the normal boiling point of Br₂ in a chemistry handbook or at the WebElements website (www.webelements.com) and compare it to your calculation. What are the possible sources of error, or incorrect assumptions, in the calculation?

Textbook Question

(c) In general, under which condition is ΔG°_f more positive (less negative) than ΔH°_f ? (i) When the temperature is high, (ii) when the reaction is reversible, (iii) when ΔS°_f is negative.