A thermodynamic process is said to occur if the thermodynamic variables of a system undergo a change with time.
Picture of thermodynamic panel
Types of thermodynamic processes
- Isobaric process: occurs at constant pressure.
- Isochoric process: Occurs at constant volume. It is also called Isovolumetric or Isometric.
- Isothermal process: This occurs at a constant temperature.
- Adiabatic process: This occurs without the loss or gain of energy by heat.
- Isentropic process: Reversible adiabatic process that occurs at constant entropy.
- Isenthalpic process: Constant enthalpy.
- Steady-state process: This occurs without a change in internal energy.
A quasi-static process is an infinitely slow process such that the system remains in thermal and chemical equilibrium with the surroundings.
ISOTHERMAL PROCESS: This occurs at a constant temperature.
Conditions for an isothermal process
- The walls of the vessel must be perfectly conducting to allow the free exchange of heat between the system and the system and the surroundings.
- The process of compression or expansion should be very slow, as to provide sufficient time for the exchange of heat.
ADIABATIC PROCESS: In this, there is no exchange of heat energy between the system and surroundings.
Conditions of the adiabatic process:
- The walls of the vessel must be perfectly insulated so that there cannot be any exchange of heat between the gas and the surroundings.
- The process of compression & expansion should be sudden, so that heat does not get time to get exchanged with the surroundings.
Any process which can be made to process in the reverse direction by variation in its conditions such that any change occurring in any part of the direct process is exactly reversed in the corresponding part of the reverse process.
Any process which cannot be retraced in the reverse direction exactly is called an irreversible process.
Any process in which the system returns to its initial state after undergoing a series of changes is known as a cyclic process.
A non-cyclic process is one in which the system does not return to its initial state.