Heat

The heat, Q is given by

$\delta Q=TdS$

where T is the temperature and S is the entropy. $\delta$ represents an inexact differential, indicating that the resulting value depends on the path taken. This equation results in an equality then the process is reversible. If the process is irreversible one has

$\delta Q<TdS$

See also

• First law of thermodynamics
• Second law of thermodynamics
• Heat flow

References

Related reading

• Leonard K. Nash "Reversible and irreversible heating and cooling", Journal of Chemical Education 47 pp. 357-361 (1970)