We present a gel-free experimental system to study the kinetics of the reac
tion front in the A + B --> C reaction-diffusion system with initially-sepa
rated reactants. The experimental setup consists of a CCD camera monitoring
the kinetics of the front formed in the reaction-diffusion process Cu2+ tetra [disodium ethyl bis(5-tetrazolylo) acetate trihydrate] --> 1:1 comple
x, in aqueous, gel-free solution, taking place inside a 150 mum gap between
two flat microscope slides. The experimental results agree with the theore
tical predictions for the time dependence of the front's width, height, and
location, as well as the global reaction rate.