Abstract: Continuous process for the preparation of pentafluoroethyl iodide from iodine, iodine pentafluoride and tetrafluoroethylene, which comprises dissolving the iodine in iodine pentafluoride and continuously feeding the resulting solution to a vertical bubble column (1), which is filled with iodine pentafluoride and at its lower end has a feed line for tetrafluoroethylene, where the reaction zone is maintained at from 85 to 95° C., preferably 90° C., and the pentafluoroethyl iodide formed escapes in gaseous form at the top of the reactor (1), is liquefied in a downstream cooled condenser and is drawn off into storage vessels.

Abstract: Lead dioxide residues are advantageously removed from conducting surfaces by cathodic reduction. The surface thus cleaned can directly have a new lead dioxide layer applied by cathodic oxidation.

Abstract: A process for continuous telomerization is described, in which at least one telogenic compound and at least one taxogenic compound are reacted at from 40.degree. to 150.degree. C. under a pressure of from 0.1 to 3 MPa in the presence of at least one catalyst in an elongate cylindrical reaction space. After it has left the reaction space, the reaction mixture is separated, for example by distillation, the desired higher-molecular telomers are discharged as the bottom product, and the undesired low-molecular telomerization products are stripped off over the top, condensed and recycled into the process in a first circulation. In a second circulation, a part of the reaction mixture is taken off towards the end of the reaction space and reintroduced into the initial part of the reaction space. This allows an improved space-time yield and a better selection of defined product cuts.