The evolution of the state of aerosol droplets containing a reaction mixture with volatile components is accompanied by a change in the size and composition of the droplets, changes in the concentrations of reagents and the rates of chemical reactions. The methods of formal chemical kinetics and equilibrium thermodynamics describe size effects that lead to a significant acceleration of chemical processes in aerosols. The dependence of the rate of chemical processes on the initial size and composition of droplets, as well as on the composition of the gas phase, is described. The main regularities are modeled on the example of the condensation reaction of glycine with glucose (Maillard reaction). Keywords: aerosol, size effect, chemical kinetics, spray technology.