  We describe the kinetics and thermodynamics of copolymers undergoing
recombination reactions, which are important for prebiotic chemistry. We use
two approaches: the first one, based on chemical rate equations and the
mass-action law describes the infinite size limit, while the second one, based
on the chemical master equation, describes systems of finite size. We compare
the predictions of both approaches for the relaxation of thermodynamic
quantities towards equilibrium. We find that for some choice of initial
conditions, the entropy of the sequence distribution can be lowered at the
expense of increasing the entropy of the length distribution. We consider
mainly energetically neutral reactions, except for one simple case of
non-neutral reactions.
