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Zinc hydroxide Zn 2 is an inorganic chemical compound. It also occurs naturally as 3 rare minerals: wülfingite (orthorhombic), ashoverite and sweetite (both tetragonal). Like the hydroxides of other metals, such as lead , aluminium , beryllium , tin and chromium , Zinc hydroxide (and Zinc oxide ), is amphoteric .
The reaction produces a primary, secondary, or tertiary alcohol via a 1,2-addition. The Barbier reaction is advantageous because it is a one-pot process: the organozinc reagent is generated in the presence of the carbonyl substrate. Organozinc reagents are also less water sensitive, thus this reaction can be conducted in water.
Simonkolleite is virtually insoluble in water and organic solvents, soluble in mineral acids yielding the corresponding zinc salts , soluble in ammonia, amine and EDTA solutions under complex formation. It can easily be converted to zinc hydroxide by reacting with sodium hydroxide . Its pH in water is 6.9 measured by EPA method SW846-9045.
A hot water solution containing 73.1% (mass) of NaOH is a eutectic that solidifies at about 62.63 °C as an intimate mix of anhydrous and monohydrate crystals. [ 21 ] [ 20 ] A second stable eutectic composition is 45.4% (mass) of NaOH, that solidifies at about 4.9 °C into a mixture of crystals of the dihydrate and of the 3.5-hydrate.
2 Na (s) + 2 H 2 O (l) →2 NaOH (aq) + H 2 (g) Metals in the middle of the reactivity series, such as iron , will react with acids such as sulfuric acid (but not water at normal temperatures) to give hydrogen and a metal salt , such as iron(II) sulfate :
Zinc is a strong reducing agent with a standard redox potential of −0.76 V. Pure zinc tarnishes rapidly in air, rapidly forming a passive layer. The composition of this layer can be complex, but one constituent is probably basic zinc carbonate, Zn 5 (OH) 6 CO 3. [8] The reaction of zinc with water is slowed by this passive layer.
Zn + 2 H 2 O + 2 NaOH → Na 2 Zn(OH) 4 + H 2. From such solutions, one can crystallize salts of containing the anions Zn(OH) 4 2−, Zn 2 (OH) 6 2−, and Zn(OH) 6 4−. Na 2 Zn(OH) 4 consists of tetrahedral zincate ion and octahedral sodium cations. [3] The salt Sr 2 Zn(OH) 6 features zinc in an octahedral coordination sphere.
Zinc chloride is an inorganic chemical compound with the formula ZnCl 2 ·nH 2 O, with n ranging from 0 to 4.5, forming hydrates. Zinc chloride, anhydrous and its hydrates, are colorless or white crystalline solids, and are highly soluble in water. Five hydrates of zinc chloride are known, as well as four polymorphs of anhydrous zinc chloride. [5]