Open, Closed & Isolated Systems
A system refers to any parts of the universe being studied.
If you are conducting an experiment in a beaker, then the system you are studying is in the beaker.
The system is subject to surrounding factors such as air temperature and pressure.
Thermodynamics involve the study of heat energy exchange between a system and its surroundings.
Types of Thermodynamic Systems
You may have heard of open systems and closed systems. An open system is one that freely allows both energy and matter to be transferred in an out of a system.
For example, boiling water without a lid.
Heat escaping into the air.
Steam (which is matter) escaping into the air.
A closed system, on the other hand, does not allow the exchange of matter but allows energy to be transferred.
It allows heat to be transferred from the stove to the water
Heat is also transferred to the surroundings
Steam is not allowed to escape
Example of a closed system – a pressure cooker.
Nb: If a system is 100% closed, it is in danger of exploding. That's why a pressure cooker should be designed with safety mechanisms to prevent the system from over-pressurzing by allowing steam to escape when needed.
This system is completely sealed.
Neither matter nor heat can transfer to or from the surroundings.
Example – A thermo flask.
The purpose of a thermo flask is to keep your food warm.
A thermo flask can be considered an isolated system but only for a short period of time.
It prevents both heat and matter from being transferred to the surrounding.
Ultimately, the heat in the thermo flask will escape to the surroundings and the content inside the flask will be cooled down.