Abstract: A method is provided for hydrolyzing chlorosilanes, for example, dimethyldichlorosilane, to produce dimethylpolysiloxane hydrolyzate and an aqueous solution of hydrogen chloride along with anhydrous hydrogen chloride. Chlorosilane hydrolysis is effected in the presence of a substantially stoichiometric equivalence of water which results in the direct generation of anhydrous hydrogen chloride and a saturated aqueous hydrogen chloride solution. The saturated aqueous solution of hydrogen chloride can be recycled to the chlorosilane hydrolysis step.

Abstract: A process is described for converting the alkyl-rich disilanes in the residue obtained from the manufacture of alkylhalosilanes to halogen-rich polysilanes with alkyltrihalosilanes and simultaneously converting the alkyltrihalosilanes to dialkyldihalosilanes by reacting the alkyl-rich polysilanes in the residue and the alkyltrihalosilanes at an elevated temperature in the presence of a suitable catalyst and a catalytic amount of a hydrosilane reaction promoter. In a preferred embodiment, the residue containing alkyl-rich disilanes is treated with methyltrichlorosilane at a temperature of about 100.degree. C. to about 250.degree. C. in the presence of aluminum trichloride catalyst and a catalytic amount of methyldichlorosilane.