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Virtually all the aluminium hydroxide used commercially is manufactured by the Bayer process [10] which involves dissolving bauxite in sodium hydroxide at temperatures up to 270 °C (518 °F). The waste solid, bauxite tailings , is removed and aluminium hydroxide is precipitated from the remaining solution of sodium aluminate .
Electronegativity is not a uniquely defined property and may depend on the definition. The suggested values are all taken from WebElements as a consistent set. Many of the highly radioactive elements have values that must be predictions or extrapolations, but are unfortunately not marked as such.
The process ends with precipitation of aluminium hydroxide, Al(OH) 3. This is useful for clarification of water, as the precipitate nucleates on suspended particles in the water, hence removing them. Increasing the pH even further leads to the hydroxide dissolving again as aluminate, [Al(H 2 O) 2 (OH) 4] −, is formed.
They consist of hydroxide (OH −) anions and metallic cations, [1] and are often strong bases. Some metal hydroxides, such as alkali metal hydroxides, ionize completely when dissolved . Certain metal hydroxides are weak electrolytes and dissolve only partially in aqueous solution .
The anomalously high electronegativity of lead, in particular when compared to thallium and bismuth, is an artifact of electronegativity varying with oxidation state: its electronegativity conforms better to trends if it is quoted for the +2 state with a Pauling value of 1.87 instead of the +4 state.
Under some definitions, the value of the radius may depend on the atom's state and context. [1] Atomic radii vary in a predictable and explicable manner across the periodic table. For instance, the radii generally decrease rightward along each period (row) of the table, from the alkali metals to the noble gases; and increase down each group ...
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The hydroxide ion is naturally produced from water by the self-ionization reaction: [1] H 3 O + + OH − ⇌ 2H 2 O. The equilibrium constant for this reaction, defined as K w = [H +][OH −] [note 1] has a value close to 10 −14 at 25 °C, so the concentration of hydroxide ions in pure water is close to 10 −7 mol∙dm −3, to