Ionic solids compounds

These reactions show sulfur in the role of an oxidizing agent. The properties of compounds such as ZnS suggest they contain the sulfide ion, S-2. The formation of this ion again can be expected on the basis of the fact that the neutral sulfur atom has two electrons less than enough to fill the valence orbitals. Acquisition of two electrons completely fills the low energy valence orbitals and solid ionic compounds can be formed. 

Let us apply these ideas to the third-row elements. On the left side of the table we have the metallic reducing agents sodium and magnesium, which we already know have small affinity for electrons, since they have low ionization energies and are readily oxidized. It is not surprising, then, that the hydroxides of these elements, NaOH and Mg(OH)z, are solid ionic compounds made up of hydroxide ions and metal ions. Sodium hydroxide is very soluble in water and its solutions are alkaline due to the presence of the OH- ion. Sodium hydroxide is a strong base. Magnesium hydroxide, Mg(OH)2, is not very soluble in water, but it does dissolve in acid solutions because of the reaction... 

Activation energies have been studied in the case of solid ionic compounds, where the target compounds and their side products are somewhat more stable and easier to handle. No measurements of activation energies have as yet been made on organometallic compounds, and unfortunately, very few annealing studies have been done. 

C04-0120. Devise a synthesis, write the net ionic reaction, and compute masses of each starting material needed to make 2.50 kg of each of the following solid ionic compounds (a) FePOq (b) Zn (OH)2 (c)... 

The word bonding applies to any situation in which two or more atoms are held together in such close proximity that they form a characteristic species which has distinct properties and which can be represented by a chemical formula. In compounds consisting of ions, bonding results from the attractions between the oppositely charged ions. In such compounds in the solid state, each ion is surrounded on all sides by ions of the opposite charge. (For example, see Fig. 5-1.) In a solid ionic compound, it is incorrect to speak of a bond between specific pairs of ions. 

Ionization refers to the process in which a molecular compound, such as HC1, separates or reacts with water to form ions in solution. Dissociation refers to the process in which a solid ionic compound, such as NaCl, separates into its ions in aqueous solution. 

Conductivity Metals are good conductors of electricity and heat because electrons can move freely throughout the metallic structure. This freedom of movement is not possible in solid ionic compounds, because the valence electrons are held within the individual ionic bonds in the lattice. 

As more ions enter the solution, the rate of the reverse change, recrystallisation, increases. Eventually, the rate of recrystallisation becomes equal to the rate of dissolving. As you know, when the forward rate and the backward rate of a process are equal, the system is at equilibrium. Because the reactants and the products are in different phases, the reaction is said to have reached heterogeneous equilibrium. For solubility systems of sparingly soluble ionic compounds, equilibrium exists between the solid ionic compound and its dissociated ions in solution. 

Solid ionic compound Dissociated ions in solution... 

KEY CONCEPT PROBLEM 2.22 The following drawings are those of solid ionic compounds, with green spheres representing the cations and blue spheres representing the anions in each. 

Ionic crystals have a regular shape. All the crystals of each solid ionic compound are the same shape. Whatever the size of the crystal, the angles between the faces of die crystal arc always the same. 

A solid covalent compound has both intermolecular and intramolecular forces. Do solid ionic compounds contain intermolecular forces Explain your answer. 

Solid ionic compounds do not conduct electricity, but solid metals do. 

Water is able to prise apart ions in a solid ionic compound and dissolve them. Some ionic compounds are more soluble than others. 

In aqueous solution, the process in which a solid ionic compound separates into its ions. 

To get compounds to decompose using electricity, ions must be present, and the sample must be in some liquid form. (Electricity does not pass through solid ionic compounds, even though they are composed of positive and negative ions.) The ions in a liquid are free to move and thus conduct the current. The liquid can be a molten (melted) ionic substance or a solution of an ionic substance in water or another liquid (Figure 8.3). If a solution is used, the compound that is more easily decomposed (the ionic compound or the water, for example) is the one that will react. 

To illustrate the principles of electron configurations in stable, solid ionic compounds, we will consider the formation of an ionic compound from calcium and oxygen. We can predict what compound will form by considering the valence electron configurations of the two atoms ... 

This discussion of the energies involved in the formation of solid ionic compounds illustrates that a variety of factors operate to determine the... 

Notice in Table 1 that the same about 25 joule rule also applies to the molar heat capacities of solid ionic compounds. One mole barium chloride has three times as many ions as atoms in 1 mol of metal. So, you expect the molar heat capacity for BaCl2 to be C = 3 x 25 J/K mol. The value in Table 1,75.1 J/K mol, is similar to this prediction. 

Next, consider the reaction of lithium (Group lA) with oxygen (Group VIA) to form lithium oxide, a solid ionic compound (mp > 1700°C) (see next page). We may represent the reaction as... 

As our final illustration of ionic bonding, consider the reaction of calcium (Group DA) with oxygen (Group VIA). This reaction forms calcium oxide, a white solid ionic compound with a very high melting point, 2580°C. 

Why are solid ionic compounds rather poor conductors of electricity Why does conductivity increase when an ionic compound is melted or dissolved in water ... 

Instead of providing electrons, atoms in defect sites may themselves be mobile and thus provide ionic conduction in a solid. Ionic compounds such as NaCl have high conductivity in their molten form, and such conductivity is important for the manufacture of aluminum by electrolysis of molten cryolite (Na3 A1F6). In most solids however, ionic conduction is much lower and arises largely from... 

Any ionic compound that has the same arrangement of cations and anions as NaCl is said to have the sodium chloride crystal structure. The ionic compounds in this category include AgF, AgCl, AgBr, and the oxides and sulfides of the alkaline earth metals, such as MgO, CaS, etc. The sodium chloride crystal structure is just one of many different possible arrangements of ions in solid ionic compounds. 

The chemist also needs to be able to convert between mass and moles for ionic compounds. The calculations are the same as for molecular compounds, but some of the terminology is different. Remember that solid ionic compounds and molecular Objective 8 compounds differ in the way their particles are organized and held together (Figure 9.2). 

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