Surroundings Examples: A thermodynamic system can be liquid, solid, gas and radiation. Thermodynamic system Surrounding Bucket of water Open atmosphere Air molecules in the room Outside air Human body Open atmosphere Fish in the sea Sea of water We can classify thermodynamics system into three types: It is given in Figure . Figure . Different types of thermodynamic systems Open Open system can exchange both matter and energy with the environment.
Closed system exchange energy but not matter with the environment. Isolated system can exchange neither energy nor matter with the enviroment. Closed Isolated (a) Open (a) Closed (a) Isolated Matter Matter Matter Energy Energy Energy Thermodynamic system . .
Thermal equilibrium When a hot cup of coffee is kept in the room, heat flows from coffee to the surrounding air. After some time the coffee reaches the same temperature as the surrounding air and there will be no net heat flow from coffee to air or air to coffee. It implies that the coffee and surrounding air are in thermal equilibrium with each other. - - - - Unit Heat and thermodynamics each other.
In a state of thermodynamic equilibrium the macroscopic variables such as pressure, volume and temperature will have fixed values and do not change with time. . . Thermodynamic state variables In mechanics velocity, momentum and acceleration are used to explain the state of any moving object (which you would have realized in Volume ).
In thermodynamics, the state of a thermodynamic system is represented by a set of variables called thermodynamic variables. Examples: Pressure, temperature, volume and internal energy etc. The values of these variables completely describe the equilibrium state of a thermodynamic system. Heat and work are not state variables rather they are process variables.
There are two types of thermodynamic variables: Extensive and Intensive Extensive variable depends on the size or mass of the system. Example: Volume, total mass, entropy, internal energy, heat capacity etc. Intensive variables do not depend on the size or mass of the system. Example: Temperature, pressure, specific heat capacity, density etc.
Equation of state: