- #1
Axe199
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I was solving some examples and one of the examples states that pressure is a qualitative property, i searched a lot on the internet but i didn't find any explanation , i didn't even find any proof that this is true.
Is pressure a qualitative property?
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In summary, the conversation discusses the concept of pressure as a qualitative or quantitative property in thermodynamics. The speakers mention searching for explanations and proof online, as well as a possible confusion with the terms "qualitative" and "quantitative." They also mention a screenshot of a question from a professor who is not a native English speaker. Finally, the conversation ends with a clarification on the distinction between "extensive" and "intensive" properties in thermodynamics.
- #2
berkeman
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Please provide the link to what you read. It sounds like clumsy commentary by a non-scientist.Axe199 said:
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I think the book meant "quantitative," not "qualitative."Axe199 said:
- #4
abdo799
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it's not an example from a textbook, it's a solved question from an old exam ( the model answer is by a professor ( not just a PhD) ) , so here's a screenshot of the question , (PS there is another model of this exam with a similar question where he said that temperature is a qualitative property)
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jtbell
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Is the professor's native language English? I've never seen the distinction "qualitative" versus "quantitative" used for thermodynamic properties. To me, it doesn't make any sense to call pressure "qualitative." You can measure it and associate a number to it, which is the meaning of "quantitative."
The usual distinction in thermodynamic properties is "extensive" versus "intensive". Enthalpy is an example of an extensive property, and pressure is an example of an intensive property.
The usual distinction in thermodynamic properties is "extensive" versus "intensive". Enthalpy is an example of an extensive property, and pressure is an example of an intensive property.
- #6
abdo799
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i know...i took a thermodynamics course on coursera...didnt mention it either, in our lecture's the professor mentioned that enthalpy is quantitative while entropy is qualitative, but he never mentioned anything else, and no..english is his second languagejtbell said:
1. Is pressure a qualitative or quantitative property?
Pressure can be considered both a qualitative and quantitative property, depending on the context in which it is being measured. In terms of its definition, pressure is a quantitative property because it can be measured and expressed in units such as pounds per square inch or pascals. However, it can also be considered a qualitative property as it describes the quality or intensity of a force being applied to a given area.
2. How is pressure different from force?
Pressure and force are related concepts, but they are not interchangeable. Force is a vector quantity that describes the strength of a push or pull on an object, while pressure is a scalar quantity that measures the force distributed over a given area. In other words, pressure is the amount of force per unit of area.
3. What are some examples of pressure in daily life?
Some common examples of pressure in daily life include the pressure exerted by a gas in a container, the pressure of water in a pipe, and the pressure of the air in our atmosphere. We also experience pressure when sitting or standing on a surface, as our weight is distributed over a certain area.
4. Can pressure be negative?
Yes, pressure can be negative. Negative pressure, also known as suction, occurs when the force acting on a surface is in the opposite direction of the normal force. This can be seen in a vacuum, where the pressure is lower than atmospheric pressure, causing objects to be pulled towards it.
5. How is pressure measured?
Pressure is typically measured using a device called a manometer, which can be a simple tube filled with a liquid or a more complex electronic instrument. The most common unit for pressure is the pascal (Pa), but other units such as atmospheres (atm) and pounds per square inch (psi) are also used depending on the context.
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