The optimum parameters in the synthesis of 1,1,1-trichloroethane during the reaction between vinylidene chloride and hydrogen chloride are as follows : temperature, 22 degrees C; catalyst (FeCl3) concentration, 0.3% by weight;, equimolar ratio of raw materials; VDC flow rate, 0.22-0.23 cm(3) cm(-3) h(-1). Changing these parameters does not result in considerable change in the product yield.