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Fluorides, solubility product

The pressed disc (or pellet) type of crystalline membrane electrode is illustrated by silver sulphide, in which substance silver ions can migrate. The pellet is sealed into the base of a plastic container as in the case of the lanthanum fluoride electrode, and contact is made by means of a silver wire with its lower end embedded in the pellet this wire establishes equilibrium with silver ions in the pellet and thus functions as an internal reference electrode. Placed in a solution containing silver ions the electrode acquires a potential which is dictated by the activity of the silver ions in the test solution. Placed in a solution containing sulphide ions, the electrode acquires a potential which is governed by the silver ion activity in the solution, and this is itself dictated by the activity of the sulphide ions in the test solution and the solubility product of silver sulphide — i.e. it is an electrode of the second kind (Section 15.1). [Pg.560]

Self-Test 11.11B The solubility product of lead(Il) fluoride, PbF, is 3.7 X 10 s. Estimate the molar solubility of the salt. [Pg.588]

Most lanthanide compounds are sparingly soluble. Among those that are analytically important are the hydroxides, oxides, fluorides, oxalates, phosphates, complex cyanides, 8-hydroxyquinolates, and cup-ferrates. The solubility of the lanthanide hydroxides, their solubility products, and the pH at which they precipitate, are given in Table 2. As the atomic number increases (and ionic radius decreases), the lanthanide hydroxides become progressively less soluble and precipitate from more acidic solutions. The most common water-soluble salts are the lanthanide chlorides, nitrates, acetates, and sulfates. The solubilities of some of the chlorides and sulfates are also given in Table 2. [Pg.3]

The lanthanide fluorides Eire all sparingly soluble in water, as are the fluorides of yttrium and scEmdiiun. Thus, solubility information is generally presented in the form of the solubility product Ksp. [Pg.93]

This expression has been written in terms of concentration if activity coefficients sue known or estimated, then a thermodynamically ideal solubility product may be obtained from the Emalogous product of ionic activities. As the concentration of ions in solutions of lanthanide fluorides is low, the concentration and activity solubility products will not differ markedly, although activity coefficients for these salts of 3 + cations are significantly less than unity even in such dilute solutions (4a). [Pg.93]

Fluorides of the lantlmnides, yttrium, and scsmdium normally precipitate from aqueous media as the hemihydrates, LnF3-MsH20. It is these hemihydrates which are in equilibrium with saturated solution, and the solubility-product measurements refer to these hemihydrates. [Pg.93]

There have been many determinations of solubility products for lanthanide fluorides over the years. We shall try to show the range of values presented for a given element, as well as the chemically important variation of solubility with the nature of the metal. Values for aqueous solution will be reviewed first, then the effects of added acid or salts on solubility considered. [Pg.94]

Variation op the Solubility Product for Lanthanum Fluoride with Sodium Perchlorate Concentration0... [Pg.96]

The logarithm of the solubility product for hydroxyapatite is -58.6 and that of fluorapatite (CajtPO jF) is -60.6 (57), and thus, D = 0.01 in favour of fluoride incorporation into the solid apatite precipitate. Accordingly, it should be difficult to prepare solid solutions of these compounds by precipitation from aqueous solution and if prepared batchwise, they are expected to contain logarithmic gradients in their internal composition. Yet, Moreno et al.(M3) report linear changes in the lattice parameters of such solid solutions. They also determined their solubility behavior. [Pg.544]

By running a potentiometric precipitation titration, we can determine both the compositions of the precipitate and its solubility product. Various cation- and anion-selective electrodes as well as metal (or metal amalgam) electrodes work as indicator electrodes. For example, Coetzee and Martin [23] determined the solubility products of metal fluorides in AN, using a fluoride ion-selective LaF3 single-crystal membrane electrode. Nakamura et al. [2] also determined the solubility product of sodium fluoride in AN and PC, using a fluoride ion-sensitive polymer membrane electrode, which was prepared by chemically bonding the phthalocyanin cobalt complex to polyacrylamide (PAA). The polymer membrane electrode was durable and responded in Nernstian ways to F and CN in solvents like AN and PC. [Pg.186]

Reactions on or close to solid surfaces maybe inhibited by deposition ofinsoluble or poorly soluble products on the reactant surface, a phenomenon referred to as overgrowth. Examples include the reaction of amines with chloranil [7], the diazotisation of poorly soluble aromatic amines in which the product diazonium salt is also insoluble and halogen exchange reactions of chloroaromatic compounds using potassium fluoride in dipolar aprotic solvents where the potassium chloride product may coat the potassium fluoride [8]. [Pg.109]

Trivalent lanthanides are favoured under normal environmental conditions and many lanthanide(III) compounds are known. Many of the compounds are soluble but the hydroxide, carbonates, fluorides and phosphates are insoluble. Solubility products of some... [Pg.874]

EXAMPLE 7-2 The solubility product of calcium fluoride is 4 x 10 Calculate its solubility S, neglecting hydrolysis of fluoride and assuming 5 equal to zero. [Pg.128]

Example 7.2. Solubility of Sulfates, Chlorides, Fluorides, and Chromates Characterize the solubility of the following salts as a function of the concentration of the common anion from the respective solubility products (AT o)... [Pg.353]

A saturated solution of Bap2 at 25°C is prepared by equilibrating solid Bap2 with water. Powdered NaF is then dissolved in the solution until the solubility of Bap2 is 1.0% of that in H2O alone. The solubility product K p of Bap2 is 1.7 X 10 at 25°C. Calculate the concentration of fluoride ion in the solution after addition of the powdered NaF. [Pg.701]

We often shorten the term solubility product constant to solubility product. Thus, the solubility products for barium sulfate, BaS04, and for calcium fluoride, Cap2, are written as... [Pg.825]


See other pages where Fluorides, solubility product is mentioned: [Pg.928]    [Pg.58]    [Pg.78]    [Pg.245]    [Pg.94]    [Pg.96]    [Pg.150]    [Pg.154]    [Pg.161]    [Pg.298]    [Pg.317]    [Pg.737]    [Pg.245]    [Pg.276]    [Pg.4]    [Pg.241]    [Pg.86]    [Pg.835]    [Pg.1507]    [Pg.210]    [Pg.690]    [Pg.701]    [Pg.296]    [Pg.4]   


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