The crystals are collected, washed, pressed and recrystallized, whereby the impurities are easily removed.
It can be recrystallized by solution in alkalies.
The disulphonate is more readily obtained by moistening the nitrilosulphonate with dilute sulphuric acid and letting it stand for twenty-four hours, after which it is recrystallized from dilute ammonia.
The solutions are made by dissolving the purest recrystallized sulphate of copper and sulphate of zinc in distilled water.
This is distilled to dryness and the distillate repeatedly recrystallized from cymene.
The urea oxalate is recrystallized and decolorized and finally decomposed by calcium carbonate (J.
Meta-dinitrobenzene is formed by the direct nitration of nitrobenzene with fuming nitric acid, the product being poured into water and recrystallized from dilute alcohol.
This is recrystallized and roasted to vanadium pentoxide, which is then suspended in water into which ammonia is passed, when ammonium metavanadate is again formed and may be purified by recrystallization.
The electrolyte, when too impure for further use, is commonly recrystallized, or electrolysed with insoluble anodes to recover the copper.