Alkali and alkaline earth metals oxides

Bauman, J. E. "Alkali- and Alkaline-Earth Metal Oxides and Hydroxides in Water" in "Solubility Data Series ... 

By careful choice of the storage material, catalysts with differing storage capacities and thermal properties can be designed for applications with different temperature ranges. Typical adsorber materials are the alkali and alkaline-earth metal oxides, e.g. barium, magnesium, potassium and cesium. 

Group lA and IIA (alkali and alkaline earth metal) oxides... 

It was suggested that the role of the partly reducible metal oxide additive is to contribute to the formation of new active sites and increase N2O dissociation. On the other hand, alkali and alkaline earth metal oxides stabilise gold particles against sintering. 

It is concluded that acidic oxides that possess a certain extent of basic property are favorable for promoting the condensation reaction a more basic property is required than in the case of the reaction with carboxylic acid. The acidic oxides such as H-zeolite, Si-Al, B, Mo-P, and W-P oxides, and heteropoly compounds are lacking in a basic property as catalyst for the reaction. On the other hand, alkali and alkaline earth metal oxides and amphoteric oxides combined with K2O are lacking in acidic property. 

Unlike the case of the reaction of HCHO with acetaldehyde, the silica-supported alkali and alkaline earth metal oxides are not effective as catalysts for this reaction, except for the Si-Mg catalyst. The yield of acrolein increases with an increase... 

Table 2 shows the chemical compositions of the porcelains measured by X-ray fluorescence spectroscopy (XRF 1500, Shimadzu), showing that all porcelains had aluminosilicate compositions with alkali and alkaline-earth metal oxides, besides other minor oxides. For porcelains containing leucite particles (C, D, and B), parts of Si02, AI2O3, and K2O contents composed these particles. Considering the fraction and stoichiometry of leucite (KAlSi206 = K20.Al203.4Si02), the compositions of glassy matrix of these porcelains were calculated and are also shown in Table 2. Note that all porcelains had in the glassy matrix an initial K2O content, and also potentially exchangeable Na ions by K ions from an external source.

It should be noted, however, that small traces of alkali metal or alkaline earth metal oxides may act to aid the sintering of the silica and permit it to occur at a lower temperature than otherwise would be possible. While the final sintered, dense, ceramic body will contain at least 99% Si02 it will be understood that trace amounts of alkali and alkaline earth metal oxides as discussed earlier are not excluded. 

The 1,2-epoxides, or vicinal epoxides, include the alkylene oxides, the simplest of which is ethylene oxide. The first reported polymerization of ethylene oxide was by Wurtz in 1863 (1), who described the reaction of ethylene oxide heated in a sealed tube with water and, later, with alkali and with zinc chloride catalysts. Seventy years later, the polymerization by a large number of catalysts, including alkali and alkaline earth metal oxides and carbonates, became one of the cornerstones in the development of the macromolecular hypothesis by Herman Staudinger (2). 

The sulphates of the alkali and alkaline earth metals and man-ganese(II) are stable to heat those of heavier metals decompose on heating, evolving sulphur trioxide and leaving the oxide or the metal ... 

Chemical Properties. In addition to the reactions Hsted in Table 3, boron trifluoride reacts with alkali or alkaline-earth metal oxides, as well as other inorganic alkaline materials, at 450°C to yield the trimer trifluoroboroxine [13703-95-2] (BOF), MBF, and MF (29) where M is a univalent metal ion. The trimer is stable below — 135°C but disproportionates to B2O2 and BF at higher temperatures (30). 

Alkali and alkaline earth metallates are obtained by heating the appropriate oxides, in the pres-enee of oxygen where neeessary. For instanee, the reaetion... 

Heating with the following solids, their fusions, or vapours (a) oxides, peroxides, hydroxides, nitrates, nitrites, sulphides, cyanides, hexacyano-ferrate(III), and hexacyanoferrate(II) of the alkali and alkaline-earth metals (except oxides and hydroxides of calcium and strontium) (b) molten lead, silver, copper, zinc, bismuth, tin, or gold, or mixtures which form these metals upon reduction (c) phosphorus, arsenic, antimony, or silicon, or mixtures which form these elements upon reduction, particularly phosphates, arsenates,... 

Now consider strong and weak bases. The common strong bases are oxide ions and hydroxide ions, which are provided by the alkali metal and alkaline earth metal oxides and hydroxides, such as calcium oxide (see Table J.l). As we have seen,... 

A note on good practice The oxides and hydroxides of the alkali and alkaline earth metals are not Bronsted bases the oxide and hydroxide ions they contain are the bases (the cations are spectator ions). However, for convenience, chemists often refer to the compounds themselves as bases. 

Foreign cations can increasingly lower the yield in the order Fe, Co " < Ca " < Mn < Pb " [22]. This is possibly due to the formation of oxide layers at the anode [42], Alkali and alkaline earth metal ions, alkylammonium ions and also zinc or nickel cations do not effect the Kolbe reaction [40] and are therefore the counterions of choice in preparative applications. Methanol is the best suited solvent for Kolbe electrolysis [7, 43]. Its oxidation is extensively inhibited by the formation of the carboxylate layer. The following electrolytes with methanol as solvent have been used MeOH-sodium carboxylate [44], MeOH—MeONa [45, 46], MeOH—NaOH [47], MeOH—EtsN-pyridine [48]. The yield of the Kolbe dimer decreases in media that contain more than 4% water. 

Based on the concept of mixed-framework lattices, we have reported a novel class of hybrid solids that were discovered via salt-inclusion synthesis [4—7]. These new compounds exhibit composite frameworks of covalent and ionic lattices made of transition-metal oxides and alkali and alkaline-earth metal halides, respectively [4]. It has been demonstrated that the covalent frameworks can be tailored by changing the size and concentration of the incorporated salt. The interaction at the interface of these two chemically dissimilar lattices varies depending upon the relative strength of covalent vs. ionic interaction of the corresponding components. In some cases, the weak interaction facilitates an easy... 

Salt-inclusion solids described herein were synthesized at high temperature (>500°C) in the presence of reactive alkali and alkaline-earth metal halide salt media. For single crystal growth, an extra amount of molten salt is used, typically 3 5 times by weight of oxides. The reaction mixtures were placed in a carbon-coated silica ampoule, which was then sealed under vacuum. The reaction temperature was typically set at 100-150 °C above the melting point of employed salt. As shown in the schematic drawing in Fig. 16.2, the corresponding metal oxides were first dissolved conceivably via decomposition because of cor-... 

Oxides of the alkali and alkaline earth metals and nickel(II) oxide incandesce in cold fluorine, and iron(II) oxide when warmed. Nickel(IV) oxide also bums in fluorine. 

The alkali and alkaline earth metals are examples of relatively simple cations that occur in only one oxidation state and are surrounded by water (see Figure 6.1). The most common of these ions in soil, in order of decreasing abundance, are calcium (Ca2+), magnesium (Mg2+), potassium (K+), and sodium (Na+). Sodium is typically present in very small amounts in high-rainfall areas, whereas it may have a relatively high concentration in low-rainfall areas. 

The analysis of tetramethylammonium hydroxide (TMAH) solutions manufactured by SACHEM Inc. of Cleburne, Texas, includes the determination of trace elements. These elements cause less-than-optimum performance of integrated circuit boards manufactured by SACHEM s customers that use these solutions in their processes. Alkali and alkaline earth metals (e.g., Li, Na, K, Mg, Ca, and Ba) can reduce the oxide breakdown voltage of the devices. In addition, transition and heavy metal elements (e.g., Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ag, Au, and Pb) can produce higher dark current. Doping elements (e.g., B, Al, Si, P, As, and Sn) can alter the operating characteristics of the devices. In SACHEM s quality control laboratory, ICP coupled to mass spectrometry is used to simultaneously analyze multiple trace elements in one sample in just 1 to 4 min. This ICP-MS instrument is a state-of-the-art instrument that can provide high throughput and low detection Emits at the parts per thousand level. Trace elemental determination at the parts per thousand level must be performed in a clean room so that trace elemental contamination from airborne particles can be minimized. 

PTFE, FEP and PFA are attacked only by alkaline metals and their organic derivatives elemental fluorine and chlorine trifluoride alkali and alkaline earth metals with their oxides and carbonates above 350°C. The other halogens, aqua regia, nitrosulfuric acid mixtures, oleum (fuming sulfuric acid) and solvents are without significant effects. 

Besides oxidative coupling of methane and double bond isomerization reactions (242), a limited number of organic transformations have been carried out with alkali-doped alkaline earth metal oxides, including the gas-phase condensation of acetone on MgO promoted with alkali (Li, Na, K, or Cs) or alkaline earth (Ca, Sr, or Ba) (14,120). The basic properties of the samples were characterized by chemisorption of CO2 (Table VI). 

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