Deposition of copper(II) hydroxosulfates by urea

The composition of the products deposited from urea-containing solutions of copper(II) sulfate is studied as a function of concentration of the reacta nts, their molar ratio, and temperature and time of thermal processing. Dep ending on the conditions, the deposited solids are pure brochantite Cu-4(OH )(6)SO4.0.25H(2)O (I), antlerite Cu-3(OH)(4)SO4 (II), and poznyakite Cu-4(O H)(6)SO4.H2O (III) or Cu-7(OH)(10)(SO4)(2).H2O (IV) or mixtures of compound s I and II, of II and IV, or of III and IV. Compounds I-IV are characterize d by IR spectroscopy, chemical analysis, crystal-optical analysis, and X-ra y powder diffraction.