• Haryana Chemical Industries

Zinc Chloride

Haryana Chemical Industries offers Zinc Chloride. Zinc chloride (ZnCl2) is a colorless or white compound of zinc and chlorine that is extremely hygroscopic. Four crystalline structures have been reported, although in pure form (i.e. water-free) only the delta (hexagonal close-packed) phase can form. It can be quenched from the melt to form a glassy material. Anhydrous zinc chloride can be prepared from zinc and hydrogen chloride. Zn + 2 HCl(g) → ZnCl2(s) + H2(g) Hydrated forms and aqueous solutions may be readily prepared using standard acid-base methods, or from one of its ores, zinc sulfide: ZnS(s) + 2 HCl(aq) → ZnCl2(aq) + H2S(l) Commercial samples of zinc chloride typically contain water and zinc oxychloride, the main hydrolysis product. Such samples may be purified as follows: 100 g of crude ZnCl2. One use for zinc chloride is as a flux for soldering. This is because of its ability (when molten) to dissolve metal oxides. This property also leads to its use in the manufacture of magnesia cements for dental fillings. ZnCl2 has also been used as a fireproofing agent and for etching metals. In the laboratory, zinc chloride finds wide use, principally as a moderate-strength Lewis acid. It can catalyse (A) the Fischer indole synthesis[9], and also (B) Friedel-Crafts acylation reactions involving activated. Zinc chloride is an ionic salt, though some covalent character is indicated by its low melting point (275 °C) and its high solubility in solvents such as diethyl ether. It behaves as a mild Lewis acid, and aqueous solutions have a pH around 4. It is hydrolyzed to an oxychloride when hydrated forms are heated.