2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/147472The finite-size scaling function and the leading corrections for the single species 1D coagulation model $(A + A \rightarrow A)$ and the annihilation model $(A + A \rightarrow \emptyset)$ are calculated. The scaling functions are universal and independent of the initial conditions but do depend on the boundary conditions. A similarity transformation between the two models is derived and used to connect the corresponding scaling functions.(LaTeX problems fixed) 34 pages, LaTeX, BONN HE-93-51Condensed Mattertext