Difference between Intensive and Extensive Properties of Matter
In the physical definition of any matter, most of the physical properties are subdivided into intensive and extensive properties. The identity and function of any substance or system are defined by these properties. Let us have a look at these two sub-categories in detail.
What is an Intensive Property?
Intensive properties of any matter are those physical properties that are independent of the mass of the substance or the system. Intensive properties are also known as bulk properties. Most intensive properties are used to define the identity of that substance or system.
Intensive Property Examples
Pressure (P), temperature (T), color are all intensive properties. Other examples include density, melting point, boiling point, etc. All these parameters do not change with the mass of the body. For example, the melting point of 1 kg ice and 1 gm of ice is the same= 0ᴼC.
Chemical potential, refractive index, specific heat capacity, thermal conductivity, viscosity are all examples of intensive properties.
What is an Extensive Property?
Extensive properties of any matter are those physical properties that depend on the mass of that matter. These properties are proportional to the size or mass of the system.
Extensive Property Examples
The weight of the system increases with the mass. Similarly, the volume also increases with the mass of the substances. The heat capacity is directly proportional to the mass of a system. The energy stored in a system is dependent on the mass of the system. For example, two boxes of the same material but the different weights will also differ in their properties.
Some other examples of extensive properties are enthalpy, entropy, Gibb’s energy, internal energy, etc.
Differences between Extensive and Intensive Properties
How to Differentiate between Intensive and Extensive Properties?
It is easy to distinguish between intensive and extensive properties. One needs to double the mass of the system. The physical properties that change with an increase in mass are extensive properties. However, those physical properties that do not change with an increase in mass are intensive properties.
Other Examples of Properties
Both the intensive and extensive properties are useful in understanding the thermodynamics of a system. Thermodynamics is the study of the flow and transformation of heat forms of any matter. It depends on the matter and the factors determining its state. Parameters that define the thermodynamic properties are:
Path function- the parameter defined by the path taken by the matter or the system to reach the current state. Work done due to frictional force is an example of path function.
State functions, also known as state variables, are defined by the current state, and not the path that is taken to reach that state. Temperature is an example of state function.
The state function of the system depends on the initial and final position of the system. However, the path functions of the system depend on the path taken by the system to reach from the initial to the final state. Both the state and path functions are important parameters to study the thermodynamic properties of a system.
FAQs on Intensive And Extensive Properties Of Matter
1. Why are the properties divided into two categories: intensive and extensive?
Physical qualities of materials and systems are frequently classified as intensive or extensive based on how they change as the size (or scope) of the system changes. An intensive quantity is one whose magnitude is not dependent on the system's size. While an extensive quantity is one whose magnitude is additive for subsystems, according to IUPAC.
The size of the system or the amount of material in the system has no bearing on the intense attribute. It is not always evenly dispersed in space; in a body of matter and radiation, it might vary from place to place. Temperature, T; refractive index, n; density, ; and object hardness are examples of intense attributes.
Subsystems, on the other hand, have broad attributes such as mass, volume, and entropy that are additive. Though it is frequently useful to classify physical quantities as intensive or extensive, they do not always fall into those categories. The square root of the mass, for example, is neither intensive nor extensive. Visit the website for more information.
2. What is meant by intensive property?
A physical quantity whose value is independent of the amount of the material for which it is measured is known as an intense attribute. The temperature of a system in thermal equilibrium, for example, is the same as the temperature of any of its parts. The temperature of each subsystem is identical if the system is divided by a wall that is permeable to heat or matter; if the system is divided by a wall that is impermeable to heat and matter, the subsystems can have different temperatures.
Similarly, if a homogeneous system is divided in half, the extensive qualities, such as mass and volume, are each divided in half, while the intensive property, density, remains the same in each subsystem. Furthermore, a substance's boiling point is an example of an intense attribute. Water, for example, has a boiling point of 100 °C at one-atmosphere pressure, which remains constant regardless of quantity.
There are some theoretical applications for the distinction between intensive and extensive properties. In thermodynamics, for example, the state of a basic compressible system is entirely determined by two independent, intensive properties and one extensive property, such as mass. These two intensive variables are used to generate further intensive features.
3. What is meant by extensive property?
A physical quantity whose value is proportional to the size of the system it describes, or to the amount of matter in the system, is known as an extensive property. The mass of a sample, for example, is a large quantity that is determined by the amount of substance present. The density is independent of the amount and is a related intense quantity. Whether you are talking about a drop of water or a swimming pool, the density of water is around 1g/mL, however, the mass is different.
When you divide one extensive property by another extensive property, you get an intensive value—for example, when you divide mass (extensive) by volume (extensive), you get density (intensive).
4. What is meant by conjugate properties?
Some extended quantities in thermodynamics measure the amounts that are conserved in a thermodynamic transfer process. They are exchanged between two thermodynamic systems, or subsystems, over a wall. A semipermeable membrane, for example, could be used to transmit different types of materials. Similarly, volume can be thought of as being transferred through a process in which the wall between two systems is moved, increasing one system's volume while decreasing the other's by the same amount.
On the other hand, extensive quantities measure amounts that are not saved during a thermodynamic transfer between a system and its surroundings. When a quantity of energy is transmitted from the surroundings into or out of a system as heat, a corresponding quantity of entropy in the system grows or drops, although not in the same amount as in the surroundings in a thermodynamic process. Similarly, a change in the amount of electric polarization in a system is not always accompanied by a change in the surrounding electric polarization.
5. What are the limitations of dividing it into intensive and extensive properties?
Extensive quantities, on the other hand, measure amounts that are not conserved during a thermodynamic transfer between a system and its surroundings. When a quantity of energy is transmitted from the surroundings into or out of a system as heat, a corresponding quantity of entropy in the system grows or drops, although not in the same amount as in the surroundings in a thermodynamic process. Similarly, a change in the amount of electric polarization in a system is not always accompanied by a change in the surrounding electric polarization.
Other systems, for which standard definitions do not provide a straightforward solution, include those in which subsystems interact when they are merged. According to Redlich, the way subsystems are arranged may affect the classification of some attributes as intensive or extensive. When two identical galvanic cells are linked in parallel, the system's voltage is equal to the voltage of each cell, but the amount of electric charge transported (or the electric current) is large. When the same cells are connected in series, the charge is concentrated and the voltage is increased. The Vedantu app and website have free study materials.
