Thermodynamics Law

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A Thermodynamics Law is a physical laws that governs thermodynamic systems.



References

2016

The four laws of thermodynamics are:
There have been suggestions of additional laws, but none of them achieves the generality of the four accepted laws, and they are not mentioned in standard textbooks.
The laws of thermodynamics are important fundamental laws in physics and they are applicable in other natural sciences.

1963

First law: Heat put into a system + Work done on a system= Increase in internal energy of the system:

[math]\displaystyle{ dQ+dW=dU }[/math]

Second law:A process whose only net result is to take heat from a reservoir and convert it to work is impossible. No heat engine taking heat [math]\displaystyle{ Q_1 }[/math] from [math]\displaystyle{ T1 }[/math] and delivering heat [math]\displaystyle{ Q2 }[/math] at [math]\displaystyle{ T2 }[/math] can do more work than a reversible engine, for which
[math]\displaystyle{ W=Q1−Q2=Q1(\frac{T1−T2}{T1}) }[/math]
The entropy of a system is defined this way:
(a) If heat [math]\displaystyle{ \Delta Q }[/math] is added reversibly to a system at temperature T, the increase in entropy of the system is [math]\displaystyle{ \Delta S= \Delta Q/T }[/math]
(b) At T=0, S=0 (third law).
In a reversible change, the total entropy of all parts of the system (including reservoirs) does not change. In irreversible change, the total entropy of the system always increases.