Thankyou!! But can you expand on the pressure example why can I not think of it as the moles being doubled in a container whose volume is constant? I.e increasing pressure by increasing mass.Mayhem said:Intensive properties are consistent for a population or a sample, extensive properties are only consistent for the sample.
For example, if I have 1 L of 1 M hydrochloric acid (population) and I take out 500 mL (half), my sample will still have the concentration of 1 M. Therefore, it is an intensive property.
If I instead consider the amount of substance, my sample of 500 mL will only contain half the substance of the population.
You can replace population/sample with whole/part.
But textbooks ask questions like state the extensive and intensive properties among so & so options which includes pressure. In that case...?Borek said:Not every property classifies as intrinsically extensive or intensive.
Mass - obviously extensive.
Density - obviously intensive.
Length? Well, you can add some restrictions so that the length becomes an extensive property (say "length of a gauge 32 wire made of material"), but in general length is impossible to classify. Similarly with pressure - you can add restrictions to the setup that will make the pressure an intensive property (when you split tank in half, the pressure is identical in each part of the tank), but you can also make a setup in which pressure becomes an extensive property (adding more ideal gas to the tank increases the pressure linearly, so the value depends on the amount of material).
tellmesomething said:But textbooks ask questions like state the extensive and intensive properties among so & so options which includes pressure. In that case...?
I see okay... Thankyou!Mayhem said:Pressure is dependent on temperature (for gases, at least) and temperature is a statistic of average kinetic energy of a particle. If the temperature is uniform in your container, then so is the pressure. Therefore, any part of such a gas should have the same pressure if partitioned into a smaller container.
Okay Thankyou!Borek said:In that case you need to take into account the description of the case, as the answer can be either intensive or extensive, depending on the setup.
If there is no precise description the question is poorly asked (and most likely expects you to answer "intensive", even if in general that's not always the correct answer).
Extensive properties are those that depend on the amount of matter in a system, such as mass, volume, and total energy. Intensive properties, on the other hand, do not depend on the amount of matter present; examples include temperature, pressure, and density.
To identify if a property is extensive or intensive, consider whether the property changes when the size of the system changes. If the property scales with the amount of substance (e.g., mass or volume), it is extensive. If it remains constant regardless of the amount of substance (e.g., temperature or density), it is intensive.
Yes, extensive properties can exhibit intensive characteristics under certain conditions, such as when normalized by the amount of substance. For example, dividing mass (an extensive property) by volume gives density, which is an intensive property.
Intensive properties are crucial because they help characterize the nature of a substance regardless of its quantity. They are often used to identify materials and predict how substances will behave under different conditions, making them essential in fields like chemistry and thermodynamics.
In thermodynamics, extensive properties are often used to describe the state of a system as a whole, while intensive properties are used to describe the state of individual components or phases within that system. Understanding the distinction helps in analyzing processes like phase changes and energy transfers.