At a particular constant temperature, the change of a substance, object or system is known as Isothermal Process. This process is basically a thermodynamic process. Usually there are two phenomena under which this process can take place.
If a system is in contact with a thermal reservoir from outside, then, to maintain thermal equilibrium, the system slowly adjusts itself with the temperature of the reservoir through heat exchange. In contrast, in another phenomenon, the system doesn’t change its temperature. This is known as Adiabatic Process.
Isothermal Process Example
This process can occur in any kind of object, system or living cells. Changes of state or phase changes of different liquids through process of melting and evaporation, are also isothermal process.
For an ideal gas, the product of pressure and volume (PV) is a constant if the gas is kept at isothermal conditions that is a constant pressure and temperature. Ideal gas literally means a hypothetical gas whose molecules don’t interact and faces a elastic collision with each other.
Isothermal Process Formula
The work involved when a gas changes from state A to state B through an isothermal process is
n = Number of moles present in the gas
R = Ideal Gas Constant
In an isothermal conditions, for an ideal gas, the product of Pressure and Volume (PV) is constant. This is known as Boyle’s Law. Boyle’s law is often termed as Boyle–Mariotte law, or Mariotte’s law. The absolute pressure exerted by a object of an ideal gas is inversely proportional to the volume it occupies if the temperature and amount of gas remain unchanged within a closed system. As per Ideal Gas Law,
PV = nRT