Laws of Thermodynamics

Zeroth Law of Thermodynamics
First Law of Thermodynamics Second Law of Thermodynamics Third Law of Thermodynamics


Zeroth Law of Thermodynamics


Zeroth Law of Thermodynamics
states that "that if two systems are at the same time in thermal equilibrium with a third system, they are in thermal equilibrium with each other."

If A and C are in thermal equilibrium with B, then A is in thermal equilibrium with B. Practically this means that all three are at the same temperature, and it forms the basis for comparison of temperatures.


Top


First Law Of Thermodynamics

Many observations of real gases have shown that the difference of the heat flow into the gas and the work done by the gas depends only on the initial and final states of the gas and does not depend on the process or path which produces the final state. This suggests the existence of an additional variable, called the internal energy of the gas, which depends only on the state of the gas and not on any process. The internal energy is a state variable, just like the temperature or the pressure. The first law of thermodynamics defines the internal energy (E) as equal to the difference of the heat transfer (Q) into a system and the work (W) done by the system.

E2 - E1 = Q - W



Top

Second law Of Thermodynamics



    Many texts define the second law as "the entropy of the universe increases during any spontaneous process."

OR

   Energy spontaneously disperses from being localized to becoming spread out if it is not hindered from doing so.

What is Entropy ???
Entropy measures the spontaneous dispersal of energy: how much energy is spread out in a process, or how widely spread out it becomes — at a specific temperature.


Top
Clicky Web Analytics