A continuous gravity decanter is to separate chlorobenzene, with a density of 1,109 kg/m3, from an aqueous wash liquid having a density of 1,020 kg/m3. If the total depth in the separator is 1 m and the interface is to be 0.6 m from the vessel floor, (a) what should the height of the heavy-liquid overflow leg be; and (b) how much would an error of 50 mm in this height affect the position of the interface