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Equilibria in Various Types of Compounds

There is an Activation Energy for defect formation. In many cases, this energy is low enough that defect formation occurs at, or slightly above, room temperature. [Pg.75]

Defects may be described in terms of thermod5mamic constants and equilibria. The presence of defects changes both the local vibrational frequencies in the vicinity of the defect and the local lattice configuration around the defect. [Pg.75]

One question we may logically eisk is how are we to know what types of defects will appear in a given solid The answer to this question is given as follows  [Pg.75]

if Frenkel Defects predominate in a given solid, other defects are usually not present. Likewise, for the Schottky Defect. Note that this applies for associated defects. If these are not present, there will still be 2 types of defects present, each having an opposite effect upon stoichiometry. Thus, we conclude that intrinsic defects usually occur in pairs. This conclusion cannot be overemphasized. The following discussion shows how this occurs in the real world of defects in solids. [Pg.75]

Up to now, we have been concerned with the MX compound as a hypothetical example of the solid state. We will now undertake more concrete examples as found in the real world, using the concepts developed for the simple MX compound. For the sake of simplicity, we restrict ourselves to binary compounds, that is- one cation and one anion. An example of a ternary compound is ABXs, where A and B are different cations, and S is a small whole number. [Pg.75]


As most organometallic compounds, lithium enolates are highly polar entities susceptible to combine in various types of (eventually solvated) aggregates that undergo dynamic equilibria in solution. This phenomenon explains why enolate solutions are difficult to describe by the classical spectroscopic, physicochemical or theoretical methods, a difficulty enhanced by the sensitivity of these equilibria to many physicochemical factors such as the concentration, the temperature or the presence of complexing additives (lithium halides, amides, amines, HMPA,. ..). The problems due to dynamics are avoided in the solid state where many clusters of lithium enolates, alone or co-crystallized with exogenous partners, have been identified by X-ray crystallography. [Pg.555]

The hydrolysis products of [PtCl2(amine)2] type of compounds undergo acid-base equilibria shown in Scheme 1. The pK3 values of various Pt(13) compounds are given in Table 2. Comparison of the data for aquated cis- and trans-DDP shows that the p/sfa values for the trans isomer are about one logarithmic unit smaller in the case of diaqua and chlo-roaqua species. By contrast, practically similar pA values have been reported for the monoaquamonohydroxo species of these isomers. [Pg.171]

The Af-HjO diagrams present the equilibria at various pHs and potentials between the metal, metal ions and solid oxides and hydroxides for systems in which the only reactants are metal, water, and hydrogen and hydroxyl ions a situation that is extremely unlikely to prevail in real solutions that usually contain a variety of electrolytes and non-electrolytes. Thus a solution of pH 1 may be prepared from either hydrochloric, sulphuric, nitric or perchloric acids, and in each case a different anion will be introduced into the solution with the consequent possibility of the formation of species other than those predicted in the Af-HjO system. In general, anions that form soluble complexes will tend to extend the zones of corrosion, whereas anions that form insoluble compounds will tend to extend the zone of passivity. However, provided the relevant thermodynamic data are aveiil-able, the effect of these anions can be incorporated into the diagram, and diagrams of the type Af-HjO-A" are available in Cebelcor reports and in the published literature. [Pg.68]

Table 3-3, given on the next page, siunmarizes the various pairs of defects possible for binary compounds. Equilibria are given along with the appropriate equilibriiun constant. Note that these equations are rather simple and can be used to specify the equilibrium constants for these defects present in the lattice. These types of defects have been observed and studied in the compounds given under "Example in this Table. These are the major types of defects to be expected in most inorganic compounds, where the number of sites in the lattice is consteuit. [Pg.105]


See other pages where Equilibria in Various Types of Compounds is mentioned: [Pg.75]    [Pg.75]    [Pg.77]    [Pg.79]    [Pg.81]    [Pg.83]    [Pg.85]    [Pg.87]    [Pg.75]    [Pg.75]    [Pg.77]    [Pg.79]    [Pg.81]    [Pg.83]    [Pg.85]    [Pg.87]    [Pg.127]    [Pg.232]    [Pg.483]    [Pg.9]    [Pg.126]    [Pg.92]    [Pg.606]    [Pg.587]    [Pg.139]    [Pg.17]    [Pg.54]    [Pg.266]    [Pg.897]    [Pg.979]    [Pg.86]    [Pg.102]    [Pg.174]    [Pg.290]    [Pg.474]    [Pg.959]    [Pg.1144]    [Pg.297]    [Pg.139]    [Pg.87]    [Pg.319]    [Pg.465]    [Pg.337]    [Pg.281]   


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Compound types

Compounding types

Equilibria types

Equilibrium compound

Various compounds

Various types

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