# 7 most common types of thermodynamic state variables

This article discusses the seven most common types of thermodynamic state variables, including extensive and intensive variables, pressure, temperature, volume, internal energy, entropy, enthalpy, and Gibbs free energy.

Thermodynamic state variables are properties of a system that define its state. These variables help in the study of thermodynamics by providing a quantitative description of the system’s behavior. In this article, we will discuss the seven most common types of thermodynamic state variables.

## Extensive Variables

Extensive variables are state variables that depend on the size or amount of matter in the system. Examples of extensive variables include mass, volume, and energy. These variables are additive, meaning that the total value of an extensive variable for a system is equal to the sum of the values for each part of the system.

## Intensive Variables

In contrast to extensive variables, intensive variables are state variables that do not depend on the size or amount of matter in the system. Examples of intensive variables include temperature, pressure, and density. These variables are not additive, meaning that their value for the entire system is the same as their value for each part of the system.

## Pressure

Pressure is a measure of the force exerted per unit area on the boundaries of a system. It is an intensive variable that can be measured in units such as Pascals or atmospheres. Pressure can be exerted by a gas, liquid, or solid, and can affect the behavior of these