  The classical mass action law is put into the context of multiscale
thermodynamics. The emergence of time irreversibility in mechanics becomes in
chemical kinetics the emergence of time reversibility in the completely
irreversible gradient time evolution of chemically reacting systems. As in
mechanics, this type of symmetry breaking is a tool for extracting an overall
pattern in the time evolution. The emerging pattern represents then a reduced
model of the time evolution. Both extended and the classical mass action laws
are also lifted to kinetic equations that take into account inertia,
fluctuations, and external forces. By a subsequent reduction to moments we form
a Grad-type hierarchy for chemical kinetics.
