Ionic compound solubility product constant

Equilibria of Slightly Soluble Ionic Compounds Solubility-Product Constant K )... 

Sigma (a) bonds Sigma bonds have the orbital overlap on a line drawn between the two nuclei, simple cubic unit cell The simple cubic unit cell has particles located at the corners of a simple cube, single displacement (replacement) reactions Single displacement reactions are reactions in which atoms of an element replace the atoms of another element in a compound, solid A solid is a state of matter that has both a definite shape and a definite volume, solubility product constant (/ p) The solubility product constant is the equilibrium constant associated with sparingly soluble salts and is the product of the ionic concentrations, each one raised to the power of the coefficient in the balanced chemical equation, solute The solute is the component of the solution that is there in smallest amount, solution A solution is defined as a homogeneous mixture composed of solvent and one or more solutes. 

Le Chatelier s principle is a powerful tool for explaining how a reaction at equilibrium shifts when a stress is placed on the system. In this experiment, you can use Le Chatelier s principle to evaluate the relative solubilities of two precipitates. By observing the formation of two precipitates in the same system, you can infer the relationship between the solubilities of the two ionic compounds and the numerical values of their solubility product constants (K ). You will be able to verify your own experimental results by calculating the molar solubilities of the two compounds using the Ksp for each compound. 

In Chapter 9, as in most of Unit 4, you learned about equilibrium reactions. In this section, you analyzed precipitation reactions. You mainly examined double-displacement reactions—reactions in which two soluble ionic compounds react to form a precipitate. You used the solubility product constant, Ksp, to predict whether or not a precipitate would form for given concentrations of ions. In Unit 5, you will learn about a class of reactions that will probably be new to you. You will see how these reactions interconvert chemical and electrical energy. 

When equilibrium is reached, solubility product constants are used to describe saturated solutions of ionic compounds of relatively low solubility. When the ion concentration in solution reaches saturation, equilibrium between the solid and dissolved ions is established. 

The solubility of an ionic compound can be described quantitatively by a value called the solubility product constant, Ksp. For the general solubility process AaBi, a An+ +b Bm, Ksp = [A, +HBm"]6. The brackets refer to concentrations in moles per liter. 

The product of and the concentration of the undissolved solid creates a new constant called the solubility product constant, The solubility product constant is an equilihrium constant for the dissolving of a sparingly soluble ionic compound in water. The solubility product constant expression is... 

The solubility product constants for some ionic compounds are listed in Table 18-3. Note that they are all small numbers. Solubility product constants are measured and recorded only for sparingly soluble compounds. 

You have learned that the solubility product constant can be used to determine the molar solubility of an ionic compound. You can apply this information as you do the CHEMLAB at the end of this chapter. also can be used to find the concentrations of the ions in a saturated solution. 

How can you use the solubility product constant to calculate the solubility of a sparingly soluble ionic compound ... 

The solubility product constant expression, describes the equilibrium between a sparingly soluble ionic compound and its ions in solution. 

You can calculate the molar solubility of an ionic compound using the solubility product constant expression. 

The foregoing example illustrates how equilibrium constants for overall cell reactions can be determined electrochemically. Although the example dealt with redox equilibrium, related procedures can be used to measure the solubility product constants of sparingly soluble ionic compounds or the ionization constants of weak acids and bases. Suppose that the solubility product constant of AgCl is to be determined by means of an electrochemical cell. One half-cell contains solid AgCl and Ag metal in equilibrium with a known concentration of CP (aq) (established with 0.00100 M NaCl, for example) so that an unknown but definite concentration of Kg aq) is present. A silver electrode is used so that the half-cell reaction involved is either the reduction of Ag (aq) or the oxidation of Ag. This is, in effect, an Ag" Ag half-cell whose potential is to be determined. The second half-cell can be any whose potential is accurately known, and its choice is a matter of convenience. In the following example, the second half-cell is a standard H30" H2 half-cell. 

The dissolution in water of a slightly soluble ionic compound reaches an equilibrium characterized by a solubility-product constant, Kgp, that is much less than 1. Addition of a common ion lowers such a compound s solubility. Lowering the pH (adding HsO" ) increases the solubility if the anion of the ionic compound is that of a weak acid. 

Solubility-Product Constants (fCjp) of Slightly Soluble Ionic Compounds... 

To what reaction does the solubility product constant, refer Table 16.1 lists sp values for several ionic solids. For any of these ionic compounds, you should be able to calculate the solubility. What is the solubility of a salt, and what procedures do you follow to calculate the solubility of a salt How would you calculate the value for a salt given the solubility ... 

Background By observing the formation of two precipitates in the same system, you can infer the relationship between the solubilities of the two ionic compounds and the numerical values of their solubility product constants Ksp). 

Solubility product Solubility product constant, iQp, reflects the relationship between dissolved species and precipitated species. Each ionic compound has its own solubility limit, which is the maximum amount of the compound that can remain in solution. IQp is commonly used in solubility calculations to determine the precipitation potential of mineral salts. Certain combinations of cations and anions form sparingly soluble salts in water, and scaling in RO/NF may occur when the salts are concentrated beyond their solubility limits. See Table 6.10. 

SOLUBILITY EQUILIBRIA (SECTION 17.4) The equilibrium between a solid compound and its ions in solution provides an example of heterogeneous equilibrium. The solubility-product constant (or simply the solubility product), K p, is an equilibrium constant that expresses quantitatively the extent to which the compound dissolves. The fCq, can be used to calculate the solubility of an ionic compound, and the solubility can be used to calculate K p. 

Solubility-Product Constants (Kgp) of Selected Ionic Compounds at 25°C... 

The equilibrium expression for a chemical equation that represents the dissolving of an ionic compound is the solubility-product constant (Kgp). For Cap2, the solubility-product constant is ... 

The Solubility-Product Constant, Ksp The solubility-product constant of an ionic compound is the equilibrium constant for the chemical equation that describes the dissolving of the compound. 

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