  Using quantum theory operator methods we discuss the general reversible
reactions $A_1+A_2+... A_r \leftrightarrow B_1+B_2+... +B_s$, where $r$ and $s$
are arbitrary natural positive numbers. We show that if either direction of the
reaction is repeated a large number of times $N$ in a finite total time $T$
then in the limit of very large $N$, keeping $T$ constant, one remains with the
initial reacting particles only. We also show that if the reaction evolves
through different possible paths of evolution, each of them beginning at the
same side of the reaction, proceeds through different intermediate consecutive
reactions and ends at the other side, then one may ``realize'' any such path by
performing in a dense manner the set of reactions along it. The same results
are also numerically demonstrated for the specific reversible reaction $A+B
\leftrightarrow A+C$. We note that similar results have been shown to hold also
in the quantum regime.
