Silver solubility product

These are practically insoluble in water, are not hydrolysed and so may be prepared by addition of a sufficient concentration of sulphide ion to exceed the solubility product of the particular sulphide. Some sulphides, for example those of lead(II), copper(II) and silver(I), have low solubility products and are precipitated by the small concentration of sulphide ions produced by passing hydrogen sulphide through an acid solution of the metal salts others for example those of zincfll), iron(II), nickel(II) and cobalt(II) are only precipitated when sulphide ions are available in reasonable concentrations, as they are when hydrogen sulphide is passed into an alkaline solution. 

Table 1. Solubility and Solubility Products of Silver(I) Compounds...

Write the equation for the dissolving of silver chromate, AgjCrO, and the solubility product expression. Silver chromate dissolves to give Ag+ and Cr04 2 ions. 

The solubility product of AgCl is 1.4 x 10-4 at 100°C. Calculate the solubility of silver chloride in boiling water. 

A plausible deduction of the solubility product relation is the following. When excess of a sparingly soluble electrolyte, say silver chloride, is shaken up with... 

Example 1. The solubility of silver chloride is 0.0015 g per L. Calculate the solubility product. 

Example 2. Calculate the solubility product of silver chromate, given that its solubility is 2.5 x 10-2gL-1. 

It is evident that silver iodide, being less soluble, will be precipitated first since its solubility product will be first exceeded. Silver chloride will be precipitated when the Ag+ ion concentration is greater than... 

If the dissociation constant of the acid HA is very small, the anion A- will be removed from the solution to form the undissociated acid HA. Consequently more of the salt will pass into solution to replace the anions removed in this way, and this process will continue until equilibrium is established (i.e. until [M + ] x [A-] has become equal to the solubility product of MA) or, if sufficient hydrochloric acid is present, until the sparingly soluble salt has dissolved completely. Similar reasoning may be applied to salts of acids, such as phosphoric(V) acid (K1 = 7.5 x 10-3 mol L-1 K2 = 6.2 x 10-8 mol L-1 K3 = 5 x 10 13 mol L-1), oxalic acid (Kx = 5.9 x 10-2 mol L-K2 = 6.4 x 10-5molL-1), and arsenic)V) acid. Thus the solubility of, say, silver phosphate)V) in dilute nitric acid is due to the removal of the PO ion as... 

When potassium cyanide solution is added to a solution of silver nitrate, a white precipitate of silver cyanide is first formed because the solubility product of silver cyanide ... 

This complex ion dissociates to give silver ions, since the addition of sulphide ions yields a precipitate of silver sulphide (solubility product 1.6 x 10 49 mol3 L 3), and also silver is deposited from the complex cyanide solution upon electrolysis. The complex ion thus dissociates in accordance with the equation ... 

The silver ions involved are derived from the silver chloride, and by the solubility product principle (Section 2.6), the activity of these ions will be governed by the chloride-ion activity... 

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). 

Other useful solid-state electrodes are based on silver compounds (particularly silver sulfide). Silver sulfide is an ionic conductor, in which silver ions are the mobile ions. Mixed pellets containing Ag2S-AgX (where X = Cl, Br, I, SCN) have been successfiilly used for the determination of one of these particular anions. The behavior of these electrodes is determined primarily by the solubility products involved. The relative solubility products of various ions with Ag+ thus dictate the selectivity (i.e., kt] = KSp(Agf)/KSP(Aw)). Consequently, the iodide electrode (membrane of Ag2S/AgI) displays high selectivity over Br- and Cl-. In contrast, die chloride electrode suffers from severe interference from Br- and I-. Similarly, mixtures of silver sulfide with CdS, CuS, or PbS provide membranes that are responsive to Cd2+, Cu2+, or Pb2+, respectively. A limitation of these mixed-salt electrodes is tiiat the solubility of die second salt must be much larger than that of silver sulfide. A silver sulfide membrane by itself responds to either S2- or Ag+ ions, down to die 10-8M level. 

Sei.f-Tfst 11.11A The solubility product of silver sulfate, Ag2S04, is 1.4 X 10 Estimate the molar solubility of the salt. 

We can gain a quantitative understanding of the common-ion effect by considering how a change in the concentration of one of the ions affects the solubility product. Suppose we have a saturated solution of silver chloride in water ... 

The equilibrium constant for this reaction is actually the solubility product, Ksp = [Ag+][C1 ], for silver chloride (Section 11.8). 

C18-0073. For the following salts, write a balanced equation showing the solubility equilibrium and write the solubility product expression for each (a) silver chloride (b) barium sulfate (c) iron(H) hydroxide and (d) calcium phosphate. 

In the tables we find i Ag+/Ag = 0.7996 V and 2 Agci/Ag = 0.2223 V. From the above it is clear that primarily the silver-silver chloride electrode functions as a pAg electrode, i.e., it measures oAg+ at an ionic strength above 0.01 (cf., extended Debye-Hiickel expressions) the calculation of [Ag+ ] becomes more difficult, and even more so for [Cl ], where the solubility product value is also involved. 

Homogeneous polycrystalline membrane electrodes [see Fig. 2.10 (3)J. The relatively high electrical conductance of monoclinic / -Ag2S and its extremely low solubility product led to the development of halide and other metal ISEs with addition of silver sulphide. 

It can be seen from this equation that the solubility product of silver chloride can be calculated from the known standard potentials of the silver... 

Electrodes responding to other halides, sulphide, cyanide, silver, lead, copper and cadmium are made using membranes fabricated from pure or doped silver sulphide (Ag2S). The membrane potential is affected by the movement of Ag+ ions between cationic lattice sites which in turn is determined by the activities of the Ag+ ion in the internal and sample solutions. As the activity of the former is fixed, that of the latter alone influences the membrane potential. The electrode will also respond to the presence of S2- ions because of their effect on the Ag+ ion activity via the solubility product expression ... 

Silver chloride is fairly insoluble (see p. 332), with a solubility product Ksp of 1.74 x 1CT10 mol2 dm-6. Its concentration in pure distilled water will, therefore, be 1.3 x 10-5 mol dm-3, but adding magnesium sulphate to the solution increases it solubility appreciably see Figure 7.10. 

In the precipitation reaction involving chloride and silver nitrate, the addition of even a small quantity of the latter shall effect precipitation of AgCl provided that Ksp has been exceeded significantly. At this juncture, the concentrations of both Ag+ and Cl are related by the solubility-product equilibrium constant thus, we have ... 

Sometimes a metal electrode may be directly responsible to the concentration of an anion which either gives rise to a complex or a precipitate with the respective cations of the metal. Therefore, they are termed as second-order electrodes as they respond to an ion not directly involved in the electron transfer process. The silver-silver chloride electrode, as already described in Section 16.3.1.1.3, is a typical example of a second-order electrode. In this particular instance, the coated Ag wire when dipped in a solution, sufficient AgCl dissolves to saturate the layer of solution just in contact with the respective electrode surface. Thus, the Ag+ ion concentration in the said layer of solution may be determined by the status of the solubility product (Kvfa equilibrium ... 

Write a balanced dissolution equation and solubility product expression for silver carbonate, Ag2C03. 

Out of the three compounds, silver chloride is the most soluble and silver iodide is the least soluble. (You can compare the solubilities of the compounds based on their solubility products because they are all the same type. Each formula unit contains two ions.)... 

The approximation (3.4.28) is fulfilled for dissolution of all silver halides in cyanide ion solutions. Even in the case of the least soluble haUde, Agl, the solubility product equals 10, while Ag(CN)j varies between 10 and I0 8s (see [5]). 

The solubility product depends on the overall silver ion concentration at the membrane surface and on the concentration of halide ions resulting from dissolution of the membrane, [X"]soi,... 

Solid-state supramolecular complexes, see Su-pramolecular copper(l)/silver(I) complexes Solubility products, 17 215 Soluble methane monooxygenase protein system, 42 263-286 hydroxylation... 

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