Water can be used to extract or "wash" water-soluble impurities from an organic reaction mixture.To carry out a "washing" operation,you add water to the reaction mixture contained in a conical vial.After capping the vial and shaking it,you aollow the organic layer and aqueous(water) layer to separate from eachother in the vial.A water wash removes highly polar and water-soluble materials,such as sulfuric acid,hydrochloric acid,or sodium hydroxide from the organic layer.A water wash can also be used to remove water-soluble and low-molecular-weight compounds,such as ethanol or acetic acid from the organic layer.The washing operation helps to purify the desired organic compound present in the original reaction mixture.