Types of the system in thermodynamics

Types of the system in thermodynamics

Open, closed and isolated system

Open system: A system is said to be an open system if it can exchange both matter and energy with the surrounding.

For ex: If some water is kept in an open vessel or if some reaction is allowed to take place in an open vessel ,exchange of both matter and energy takes place between the system and surrounding.

Closed system: If a system can exchange only energy with the surrounding but not matter it is called a closed system.

For ex: If some water is placed in a closed metallic vessel or if some reactions is allowed to take place in a cylinder enclosed by a piston ,then as the vessel is closed, no exchange of matter between the system and surrounding can take place. As the vessel has conducting walls, exchange of energy can take place between the system and the surrounding.

If the reaction is exothermic, heat is given by the system to the surrounding.

If the reaction is endothermic, heat is given by surrounding to the system.

If the reaction is accompanied by decrease in volume, mechanical work is done by the surrounding on the system.

If the reaction is accompanied by increase in volume, the mechanical work is done by the system on the surrounding.

Isolated system :If a system can neither exchange matter no energy with the surrounding ,it is called an isolated system.

For Ex: If water is placed in a vessel which is closed as well as insulated, no exchange of matter or energy can take place between the system and the surrounding.