Thermodynamics - Temperature/Entropy diagram

In summary: Your name]In summary, converting a P-V diagram to a T-S diagram involves identifying the process shown in the diagram, using the ideal gas law to calculate temperature values, using the entropy equation to calculate the change in entropy, and plotting the points on a T-S diagram to represent the process. A thermodynamics textbook can provide more information and examples on this topic.
  • #1
Jalo
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Homework Statement



If I have a diagram P-V how can I turn it into a T-S diagram? (Temperature-Entropy)

Homework Equations





The Attempt at a Solution



I know that Q=TdS <=> dS = Q/T

If a process is isothermic I'll just draw a line. If the process is adiabatic I'll draw a vertical line (constant S). For any other process I don't know what to do...

Any help would be highly appreciated! If you have a book that explains this it would be perfect!
 
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  • #2





Thank you for your question. Converting a P-V diagram to a T-S diagram can be done using the following steps:

1. Identify the process: First, you need to identify the type of process shown in the P-V diagram. Is it isothermal, adiabatic, isobaric, or some other type of process? This will help you determine the appropriate equations to use.

2. Use the ideal gas law: The ideal gas law, PV = nRT, can be used to calculate the temperature at different points on the P-V diagram. Simply rearrange the equation to solve for T: T = PV/nR. This will give you the temperature values for each point on the diagram.

3. Use the entropy equation: As you mentioned in your attempt at a solution, the equation dS = Q/T can be used to calculate the change in entropy for a process. If the process is isothermal, then the change in entropy (dS) will be equal to the heat transfer (Q) divided by the temperature (T). If the process is adiabatic, then dS will be equal to zero.

4. Plot the points on a T-S diagram: Using the temperature and entropy values calculated in step 2 and 3, plot the points on a T-S diagram. The temperature will be on the horizontal axis (S) and the entropy on the vertical axis (T). Connect the points to create a line, which will represent the process on the T-S diagram.

I hope this helps! If you need further clarification or have any other questions, please don't hesitate to ask. Additionally, any thermodynamics textbook should have more information and examples on converting between P-V and T-S diagrams. Best of luck with your studies!


 

FAQ: Thermodynamics - Temperature/Entropy diagram

1. What is a temperature/entropy diagram?

A temperature/entropy diagram, also known as a T-s diagram, is a graphical representation of the relationship between temperature and entropy in a thermodynamic system. It is commonly used to visualize the behavior of a substance as it undergoes changes in temperature and entropy.

2. How is a temperature/entropy diagram used?

A temperature/entropy diagram is used to analyze and understand the thermodynamic properties and processes of a system. It can be used to determine the efficiency of a system, identify the state of a substance, and predict the direction and extent of a process.

3. What is the significance of the shape of a temperature/entropy diagram?

The shape of a temperature/entropy diagram can give important information about the behavior of a substance. For example, a horizontal line on the diagram represents a constant temperature process, while a vertical line represents a constant entropy process. The slope of a line on the diagram also indicates the rate of heat transfer in a process.

4. How does a temperature/entropy diagram relate to the laws of thermodynamics?

A temperature/entropy diagram is a visual representation of the first and second laws of thermodynamics. The first law, also known as the law of conservation of energy, states that energy cannot be created or destroyed, only transferred or converted. The second law states that the total entropy of a closed system will always increase over time.

5. Can a temperature/entropy diagram be used for any substance?

Yes, a temperature/entropy diagram can be used for any substance as long as its thermodynamic properties are known. However, the shape and behavior of the diagram may vary depending on the substance, as different substances have different thermodynamic properties.

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