FIELD: inorganic syntheses. SUBSTANCE: Caro's acid is continuously and adiabatically prepared on relatively small installation by means of adding concentrated hydrogen peroxide into stream of concentrated sulfuric acid flowing through reaction chamber which is ring-shaped in the reactants' intake points. Near hydrogen peroxide intake opening, width of chamber is enlarged and near sulfuric acid intake opening it is narrower. The former opening is arranged at an angle and in reverse direction resulting in that the two reactants meet one another at angle within the range 90 to 165 deg. EFFECT: intensified reaction process. 21 cl, 1 dwg
