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Hydroxy ions

The product crystals find industrial application as a component raw material for optical glass, fibreglass, Braun tubes, electric condensers, barium ferrite, etc. Needles shaped crystals are obtained at high pH, while pillar-shaped crystals are formed at neutral pH. The formation of carboxyl ions is via hydroxy ions at high pH, but at neutral pH it may accompany the production of hydrogen sulphide, as... [Pg.233]

A base, in terms of the ionic theory, is a substance which yields hydroxy ions as the only negative ion, when dissolved in an ionizing solvent (usually water). The general and characteristic properties of bases are predominantly due to the properties of hydroxy ions. [Pg.587]

The acidity of a base is the number of hydroxy ions formed per molecule of the base in aqueous solution. It may also be considered as the number of H+ ions that can be accepted by one molecule of the base. Thus, NaOH and KOH are monoacid bases, Ca(OH)2 and Mg(OH)2 are diacid bases, and Al(OH)3 and Fe(OH)3 are triacid bases. [Pg.587]

A comparison of this equation with the equations provided above points out that lead (IV) oxide is clearly not a base. The nature of metallic hydroxides varies according to the position of the metal in the reactivity series, as given in Table 6.3. Metallic hydroxides are electrovalent compounds, composed of metal ions, which are positively charged, and hydroxy ions, OTT. The number of OTT ions associated with one metallic ion is equal to the valency of the metal, e.g., Na+OH sodium is monovalent Ca2+(OTT)2 calcium is divalent. The metallic hydroxides form a very important series of compounds, and are known to have many uses both in the laboratory and in industry. [Pg.592]

It is important to note that each hydrogen ion is accompanied by a hydroxy ion, so that in neutral solution the concentrations of these two ions are equal to each other, and therefore from the equation, 11 l+][OI I = Kw, each of these concentrations is equal to (Kv)"5. It is worthwhile adding additional fundamentals pertaining to the ionization of water. The equilibrium constant (Kr) of the ionization reaction of water as shown above is ... [Pg.600]

However, the resulting equilibrium is heavily biased towards H20 molecules. Experiments suggest that, on an average, out of every ten million water molecules there is just one that has split into ions. Nevertheless, a beaker of water, holding billions of water molecules, will contain a large number of hydrogen and hydroxy ions, and the presence of these ions has a profound influence on the products of electrolysis. [Pg.602]

Immediately following the end-points, further addition of sodium hydroxide introduces the fast-moving hydroxy ions and the conductivity value registers a sharp rise. The point at which the two curves intersect provides, therefore, the end-point... [Pg.622]

For molybdenite concentrates hydroxy ions must be added to maintain a near neutral pH value. The pH value at which the electroleaching of other metal sulfides is conducted depends upon the amount of hydroxy ions added. For example, when a low grade cinnabar ore is treated, the pH remains almost neutral because of the calcite content of the ore. This is also true of carbonaceous gold ores. [Pg.726]

Arrhenius definition of an acid is— a substance which yields hydrogen ion (H+) in an aqueous medium and that of a base is— a substance which yields hydroxy ions (OH-) in an aqueous medium . [Pg.95]

General procedures for the preparation of pillared clays are schematically illustrated in Fig. 1. The first and most important reaction for the introduction of pillars is ion-exchange the hydrated interlayer cations of montmorillo-nite are exchanged with precursory polynuclear metal hydroxy cations. After the ion-exchange, the montmorilIonite is separated by centrifugation and washed with water several times to remove excess hydroxy ions. The interlayered hydroxy cations are then converted into the respective oxide pillars by calcination. The precursors developed so far and the interlayer spacings of their... [Pg.90]

A Co(IH) complex is inert in ligand-substitution reactions, and its uniform structure is thus maintained even in an aqueous solution. The reaction mechanism of a Co(III) complex in solution is well known, so that a pendant-type polymer-Co(IU) complex, e.g. 17,19, is one of the most suitable compounds for a quantitative study of the effects of a polymer ligand on the reactivity of a metal complex. The reactivities of the polymer-Co(III) complexes are discussed here kinetically and compared with those of the monomeric Co(III) complexes in the following reactions electron-transfer reactions between the polymer complexes and Fe(II) [Eqs. (5) and (6)], and the ligand-substitution reaction of the polymer-Co(III) complex with hydroxy ions or water [Eqs. (7) and (8)J. One of the electron-transfer reactions proceeds via... [Pg.38]

Rhodonine(7), the medium wavelength chromophores Retinal, 7-hydroxy-, ion(l-)... [Pg.129]

For the same reason the addition of an oily phase to water-based products can help considerably in promoting perfume stability. Most perfume materials are far more readily soluble in fats and in oils than in water, and to the extent that the product formulation provides an oil or fat phase into which they can escape, they are sheltered from the attack by the hydroxy ions of bases, the hydrogen ions of acids, the oxidizing agents and enzymes—all of which operate only in the water phase. Hence cloudy cold wave lotions, which contain emulsified oil, are easier to perfume than clear ones, cream depilatories cause less severe problems than fat-free formulations, and so on. [Pg.169]

When the concentration of the supersolubility curve has been attained, nucleation proceeds rapidly and the subsequent growth of the nuclei proceeds faster than the generation or addition of hydroxy ions. [Pg.212]

Analogous experiments with silica as the support indicate the appreciable interaction of precipitating nickel(II) ions with silica [20, 21], In the experiments represented in Fig. 12 the solutions or the suspension was kept at 298 K. The curve measured with suspended silica runs again considerably below the curve calculated from the curves recorded with water, suspended silica, and nickel nitrate alone. The interaction with the silica support causes a higher consumption of hydroxy ions at a low pH level. Burch and Flambard [22] per-... [Pg.213]

With perchlorate ions, which interact less strongly with precipitating copper(II) ions, nucleation of precipitated copper species proceeds at a significantly higher pH level, as can be concluded from Fig. 16. When more alkali has been added, reaction of the basic salt initially precipitated to (brown or black) copper oxide, which is more stable, takes place. Consequently, a drop in pH level is exhibited due to the exchange of perchlorate ions for hydroxy ions. With suspended silica the pH curve runs initially below the level measured without suspended silica. The stabilization of the copper species precipitated by interaction with the support is evident from the fact that now no copper oxide results when more alkali has been added. The loaded support displays still a blue color when the precipitation has finished which is maintained after drying at 383 K. [Pg.214]

Figure 17 shows the precipitation of coppcr(II) at 363 K in the presence of suspended silica when more hydroxy ions are admitted and consequently higher pH levels are obtained [26]. It has been observed that the basic copper nitrate initially precipitated becomes unstable and reacts with the support at higher pH levels. The silica support reacts to a considerable extent with the coppcr(II) ions to a hydrosilicatc, which has a... [Pg.214]

Oraganosilicon compounds react with a wide variety of organic electrophiles in the presence of a palladium catalyst and a Lewis base activator such as a fluoride or hydroxy ion to give the corresponding coupled products. The reaction is applicable to synthesis of diynes, enynes, arylacetylenes, alkenylarenes, biaryls, allylarenes and alkylarenes in addition to 1,3-, 1,4- and 1,5-dienes with tolerance for various functional groups. [Pg.61]


See other pages where Hydroxy ions is mentioned: [Pg.135]    [Pg.591]    [Pg.593]    [Pg.593]    [Pg.596]    [Pg.596]    [Pg.616]    [Pg.622]    [Pg.672]    [Pg.732]    [Pg.330]    [Pg.511]    [Pg.347]    [Pg.90]    [Pg.345]    [Pg.305]    [Pg.86]    [Pg.331]    [Pg.369]    [Pg.369]    [Pg.132]    [Pg.445]    [Pg.70]    [Pg.61]    [Pg.212]    [Pg.212]    [Pg.213]    [Pg.214]    [Pg.217]    [Pg.219]    [Pg.219]    [Pg.219]   
See also in sourсe #XX -- [ Pg.55 ]




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