We apply a certain unifying physical description of the results of
Information Theory. Assuming that heat entropy is a thermodynamic
realization of information entropy, we construct a cyclical,
thermodynamic, average-value model of an information transfer chain as a
general heat engine, in particular a Carnot engine, reversible ar
irreversible. A working medium of the cycle (a thermodynamic system
transforming input heat energy) can be considered as a thermodynamic,
average-value model or, as such, as a realization of an information
transfer channel. We show that for a model realized in this way the
extended II. Principle of Thermodynamics is valid and we formulate its
information form. Also we solve the problem of a proof of II. Principle of
Thermodynamics. We state the relation between the term of information
entropy, introduced by C. Shannon (1948), and thermodynamic entropy,
introduced by R. Clausius (1850) and, further, explain Gibbs paradox. Our
way to deal with the given topic is a connection of both the mathematical
definitions of information entropies and their mutual relations within a
system of stochastic quantities especially with thermodynamic entropies
defined on an isolated system in which a realization of our (repeatable)
observation is performed [it is a (cyclic) transformation of heat energy
of an observed, measured system]. We use the information description to
analyze Gibbs paradox reasoning it as a property of such observation,
measuring of an (equilibrium) thermodynamic system. We state a logical
proof of the II. P.T. as a derivation of relations among the entropies of
a system of stochastic variables, realized physically, and, the
Equivalence Principle of the I., II. and III. Principle of Thermodynamics
is formulated.