Electrolytic reaction system for producing gaseous hydrogen and oxygen, comprising - a reaction chamber (2, 69) for accommodating an electrolyte, - an electrode arrangement in the reaction chamber (2, 69), which electrode arrangement is formed of a plurality of anodic and cathodic electrodes (5, 6), - wherein the electrode arrangement is formed by tubular electrodes (5, 6) arranged coaxially or approximately coaxially, wherein the cylindrical lateral surfaces or lateral surfaces composed of multiple surfaces oriented at an angle to one another, of the adjacently arranged tubular electrodes (5, 6) are arranged at a distance from one another by at least one gap (57, 58), so that at least one flow channel for the electrolyte is formed between the lateral surfaces of electrodes (5, 6) spaced apart from one another, which flow channel extends between a first axial end for admitting the electrolyte into the electrode arrangement and a second axial end for discharging the electrolyte from the electrode arrangement, - wherein the at least one flow channel has at least one first flow cross-section and at least one second flow cross-section, wherein the second flow cross-section has a smaller size than the first flow cross-section, - and wherein the comparatively smaller second flow cross-section is formed in a partial section of the at least one flow channel located closer to the second axial end of the electrode arrangement, characterized in that the at least one gap (57, 58) between directly adjacent electrodes (5, 6) is at maximum and/or greater in the region of the bottom, as viewed in the vertical direction, first axial end of the electrode arrangement than in the region of the top, as viewed in the vertical direction, second axial end of the electrode arrangement, and this at least one gap (57, 58) is at minimum or smaller in the region of the top, as viewed in the vertical direction, second axial end of the electrode arrangement. - a reaction chamber (2, 69) for accommodating an electrolyte, - an electrode arrangement in the reaction chamber (2, 69), which electrode arrangement is formed of a plurality of anodic and cathodic electrodes (5, 6), - wherein the electrode arrangement is formed by tubular electrodes (5, 6) arranged coaxially or approximately coaxially, wherein the cylindrical lateral surfaces or lateral surfaces composed of multiple surfaces oriented at an angle to one another, of the adjacently arranged tubular electrodes (5, 6) are arranged at a distance from one another by at least one gap (57, 58), so that at least one flow channel for the electrolyte is formed between the lateral surfaces of electrodes (5, 6) spaced apart from one another, which flow channel extends between a first axial end for admitting the electrolyte into the electrode arrangement and a second axial end for discharging the electrolyte from the electrode arrangement, - wherein the at least one flow channel has at least one first flow cross-section and at least one second flow cross-section, wherein the second flow cross-section has a smaller size than the first flow cross-section, - and wherein the comparatively smaller second flow cross-section is formed in a partial section of the at least one flow channel located closer to the second axial end of the electrode arrangement,