An improvement in reactors for plasma-chemical processes is provided, where the arc-chamber includes electrodes for the transmission of an arc therethrough, and a supply of a plasma gas is forced through the arc, which includes injection means for supplying the reactants to a reactor, and into the plasma gas stream. The reactor may be a single reactor or a series of reactors, and may also include a cooling chamber or series of cooling chambers, downstream therefrom, the cooling chambers also including injection means for supplying coolant to the stream of plasma gas, now including reactor products. In a preferred embodiment, a series of nozzles within both the reaction chamber and cooling chamber, injects both the reactants and coolant, respectively, into these chambers tangentially to the plasma gas streams. Where a series of reactors and cooling chambers are utilized, the tangential flow in each successive reactor alternates in a clockwise and counter-clockwise direction, to achieve maximum mixing.