Thermodynamics deals with study of energy flow, and behaviour of matter. Where matter is anything that occupies space, and the region of matter which is subjected to thermodynamic analysis is called a system.
As system is a part of the universe, everything and anything other than the system is called the surrounding. Therefore,
System + Surrounding = Universe
We have mainly 3 types of system, based on the assumptions we take,
Some of the basics concepts and terms :-
As system is a part of the universe, everything and anything other than the system is called the surrounding. Therefore,
System + Surrounding = Universe
We have mainly 3 types of system, based on the assumptions we take,
- Open System : These are systems where both mass and energy can be exchanged with the surrounding. Eg. A bucket of steaming hot water - matter can escape in the form of steam and heat can flow out to the surroundings.
- Closed System : It is a system where only energy can be exchanged with the surrounding, i.e. exchange of mass is restricted by some means like a diathermic (which allows flow of heat through it ) wall or a container. Eg. If we pour the hot water in a air tight container and close it, no matter can go out but we do still feel the heat on the walls as heat can still flow out.
- Isolated System : In this system neither energy nor matter can be exchanged with the surrounding. It can be assumed as a container with adiabatic walls( which restrict the flow of heat through it. This is an ideal case as a close to it example in real life is a thermos flask or vacuum flask, hot water kept in remains hot as the heat cannot flow out.
Some of the basics concepts and terms :-
- Extensive and Intensive Properties
- Extensive Properties : These are the properties which depend on the mass ( or size ) of the system. Eg. Volume ,Internal Energy, Entropy are extensive properties as their values depend on the size of the system
- Intensive Properties : These are the properties whose values are independent of the size of the system. Eg. Temperature and Pressure
- If Extensive properties are expressed as per unit mol or per unit volume, they have the characteristics of Intensive Properties. Eg. Mass is Extensive property but density is Intensive.
- Processes :
- Isothermal : A Process where the Temperature Remains Constant
- Isobaric : A Process where the Pressure Remains Constant
- Isochoric ( Isovolumic ) : A Process where the Volume of the System Remains Constant
- Adiabatic : A process in which there is no heat flow out the system, i.e. no exchange of energy in the form of heat with the surrounding.
