  The entropy production rate is a key quantity in irreversible thermodynamics.
In this work, we concentrate on the realization of entropy production rate in
chemical reaction systems in terms of the experimentally measurable reaction
rate. Both triangular and linear networks have been studied. They attain either
thermodynamic equilibrium or a non-equilibrium steady state, under suitable
external constraints. We have shown that the entropy production rate is
proportional to the square of the reaction velocity only around equilibrium and
not any arbitrary non-equilibrium steady state. This feature can act as a guide
in revealing the nature of a steady state, very much like the minimum entropy
production principle. A discussion on this point has also been presented.
