Copper in salt water near the discharge of a sewage treatment plantis determined by first seperating and concentrating it by solventextraction of its dithizone chelate at pH 3 into methyl chlorideand then evaporating the solvent, ashing the chelate to distroy theorganic portion, and titrating the copper with EDTA. Three 1-Lportions of the sample are each extracted with 25mL portions ofmethylene chloride and the extracts are combined in a 100 mLvolumetric flask and diluted to volume. A 50- mL aliquot isevaporated, ashed and titrated. If the EDTA solution has a CaCO3titer 2.69 mg/mL and 2.67 mL is required for titration of thecopper, what is the concentration of the copper in the seawater?