Search results
Results from the WOW.Com Content Network
Aluminium oxide is an amphoteric substance, meaning it can react with both acids and bases, such as hydrofluoric acid and sodium hydroxide, acting as an acid with a base and a base with an acid, neutralising the other and producing a salt. Al 2 O 3 + 6 HF → 2 AlF 3 + 3 H 2 O Al 2 O 3 + 2 NaOH + 3 H 2 O → 2 NaAl(OH) 4 (sodium aluminate)
Closely related are aluminium oxide hydroxide, AlO(OH), and aluminium oxide or alumina (Al 2 O 3), the latter of which is also amphoteric. These compounds together are the major components of the aluminium ore bauxite. Aluminium hydroxide also forms a gelatinous precipitate in water.
Although an amphiprotic species must be amphoteric, the converse is not true. For example, a metal oxide such as zinc oxide, ZnO, contains no hydrogen and so cannot donate a proton. Nevertheless, it can act as an acid by reacting with the hydroxide ion, a base: ZnO + 2 OH − + H 2 O → [Zn(OH) 4] 2−. Zinc oxide can also act as a base:
The following chart shows the solubility of various ionic compounds in water at 1 atm pressure and room temperature (approx. 25 °C, 298.15 K). "Soluble" means the ionic compound doesn't precipitate, while "slightly soluble" and "insoluble" mean that a solid will precipitate; "slightly soluble" compounds like calcium sulfate may require heat to precipitate.
Al + NaOH + H 2 O → NaAlO 2 + 3 / 2 H 2. although the aluminium species in solution is probably instead the hydrated tetrahydroxoaluminate anion, [Al(OH) 4] − or [Al(H 2 O) 2 (OH) 4] −. [2] Oxidizing acids do not effectively attack high-purity aluminium because the oxide layer forms and protects the metal; aqua regia will
A solution containing an aqua ion does not have the long-range order that would be present in a crystal containing the same ion, but there is short-range order. X-ray diffraction on solutions yields a radial distribution function from which the coordination number of the metal ion and metal-oxygen distance may be derived. With aqua ions of high ...
The Bayer process is the principal industrial means of refining bauxite to produce alumina (aluminium oxide) and was developed by Carl Josef Bayer.Bauxite, the most important ore of aluminium, contains only 30–60% aluminium oxide (Al 2 O 3), the rest being a mixture of silica, various iron oxides, and titanium dioxide. [1]
Aluminium(I) oxide is formed by heating Al and Al 2 O 3 in a vacuum while in the presence of SiO 2 and C, and only by condensing the products. [2] Information is not commonly available on this compound; it is unstable, has complex high-temperature spectra, and is difficult to detect and identify. In reduction, Al 2 O is a major component of ...