Breakthrough of a cross-century problematic issue:The perfect statements of the third law of thermodynamics

TL;DR

This paper proposes a new, more accurate formulation of the third law of thermodynamics by deriving the Nernst and heat capacity statements directly from experimental data, resolving longstanding debates.

Contribution

It introduces an innovative method to derive the Nernst and heat capacity statements directly from experimental data, replacing traditional textbook assumptions and clarifying their equivalence.

Findings

Nernst theorem can be derived directly from experimental data.

Heat capacity statement is also obtained from experimental data.

Nernst and heat capacity statements are proven to be equivalent.

Abstract

The third law of thermodynamics has been verified experimentally, but how to perfectly express such a law in theory has become a cross-century problematic issue. It is found from the recent researches that by introducing an innovative method, the Nernst equation can be obtained directly from the experimental data of chemical reactions at low temperatures without the need for artificial additional assumptions appearing in textbooks, so that the Nernst theorem should be replaced by the Nernst statement. The heat capacity statement proposed recently can be also obtained from the experimental data of the heat capacity at low temperatures. The heat capacity statement and the Nernst statement are proved to be mutually derivable and the two are equivalent. The unattainability statement of absolute zero temperature is only a coloration of the Nernst statement or the heat capacity statement. Simultaneously, the defects and deficiencies related to the contents of the third law of thermodynamics appearing in textbooks are pointed out and corrected. The results obtained show clearly that the Nernst theorem and the unattainability statement of absolute zero temperature should be withdrawn from the statements of the third law of thermodynamics. It is important to find that the Nernst statement and the heat capacity statement are two equivalent statements of the third law of thermodynamics, which can solve the centennial debate problems of the third law of thermodynamics and supply the perfect statements for the third law of thermodynamics.