Group IA and IIA metals

From this expression, known as the Fermi-Dirac distribution function, we can see that when T = 0, /( ) = 1 when F and /( ) = 0 for F . the number of electrons with energy between and + dE per unit volume is given by /( ) g(E) dE, which can be written as 

When the total number of electrons per unit volume is given by 

A large number of compounds of the group IA and IIA metals occur naturally (salt, soda, limestone, etc.). These compounds have been important for thousands of years, and they still are. Moreover, lime is still produced by heating limestone, and the quantity produced is enormous. 

In most instances, the group IA metals form +1 ions, but this is not always the case. Because of the low ionization potential of sodium, an unusual situation exists with regard to forming Na+ and Na ion pairs. If we consider the reaction 

The Na (g) would also be solvated, but the heat associated with that process would be less than that for the cation. All this is hypothetical because sodium reacts vigorously with water. What is needed is 

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When the oxygen compounds of group IA and IIA metals react with water, strongly basic solutions are produced regardless of whether an oxide, peroxide, or superoxide is involved. 

Because of the tendency of sulfur toward catenation, solutions containing sulfides react with sulfur to give polysulfides, which can be represented as SnJ (see Chapter 15). Sulfides of the group IA and IIA metals can also be produced by reducing the sulfates with carbon at high temperature. 

Most nonmetallic elements will react with the group IA and IIA metals to give binary compounds. Heating the metals with nitrogen or phosphorus gives nitrides and phosphides of the metals. 

Binary carbides are formed when the metals are heated strongly with carbon. The most important carbide of the group IA and IIA metals is calcium carbide, CaC2. Ibis carbide is actually an acelylide because it contains the C/ ion and it reacts with water to produce acetylene. 

Some of the important compounds containing the group IA and IIA metals are the carbonates, nitrates, sulfates, and phosphates. We have already mentioned the mineral trona as the source of sodium carbonate. Calcium carbonate is found in many forms that include chalk, calcite, aragonite, and marble, as well as in egg shells, coral, and seashells. In addition to its use as a building material, calcium phosphate is converted into fertilizers in enormous quantities (see Chapter 14). 

The carbonates, sulfates, nitrates, and phosphates of the group IA and IIA metals are important materials in inorganic chemistry. Some of the most important compounds of the group IA and IIA elements are organometallic compounds, particularly for lithium, sodium, and magnesium, and Chapter 12 will be devoted to this area of chemistry. 

Jolly, W. L. (1972). Metal-Ammonia Solutions. Dowden, Hutchinson Ross, Stroudsburg, PA. A collection of research papers that serves as a valuable resource on all phases of the physical and chemical characteristics of these systems that involve solutions of group IA and IIA metals. 

Most sulhdes (S2 ) are insoluble except those sulfides composed of Group IA and IIA metals or the ammonium ion. 

In this section, we will discuss organometallic derivatives of zinc, cadmium, mercury, and indium. The group IIB and IIIB metals have the d10 electronic configuration in the 2+ and 3+ oxidation states, respectively. Because of the filled d level, the 2+ or 3+ oxidation states are quite stable, and reactions of the organometallics usually do not involve changes in oxidation level. This property makes the reactivity patterns of these organometallics more similar to those of derivatives of the group IA and IIA metals than to those of derivatives of transition metals with vacancies in the d levels. The IIB metals, however, are... 

Chelation of the main group IA and IIA metal ions in nature is not extensive, an observation attributable to their relatively weak coordination properties and their large hydration energies. However, when it comes to selecting between similar ions, e.g. Na+ and K+, then selective chelation appears to offer the most efficient route. 

We have recently prepared a new chromophoric and redox-responsive ionophore (4) containing a tricyanovinyl redox-active moiety (35) (Scheme 2). Electronic absorption spectra of (4) exhibit hypochromic shifts on binding Group IA and IIA metal cations and cyclic voltamme-tric electrochemical investigations reveal that (4) electrochemically recognizes Na+ and K+ guest cations, resulting in one-wave CV shifts of the tricyanovinyl reduction wave (80 and 20 mV, respectively) to more anodic potentials. 

Organic hydroxy and amino compounds Group IA and IIA metals Aluminium... 

Most of the Group IA and IIA metals react with hydrogen to form metal hydrides. For all of the metals in these two groups except Be and Mg, the hydrides are considered to be ionic or salt-like hydrides containing H ions (see Chapter 6). The hydrides of beryllium and magnesium have considerable covalent character. The molten ionic compounds conduct electricity, as do molten mixtures of the hydrides in alkali halides, and during electrolysis of the hydrides, hydrogen is liberated at the anode as a result of the oxidation of H ... 

All of the Group IA and IIA metals form sulfides, some of which are used rather extensively. The sulfides of Group IIA metals consist of M2+ and S2 ions arranged in the sodium chloride type lattice (see Chapter 3). The compounds of the Group IA metals consist of M+ and S2, but as a result of there being twice as many cations as anions, the structure is of the antifluorite type (see Chapter 3). The sulfide ion is a base so there is extensive hydrolysis in solutions of the sulfides, and the solutions are basic ... 

The most important sulfides of the Group IA and IIA metals are Na2S and BaS. They can be prepared by the reduction of the sulfates by heating them with carbon at very high temperature ... 

The nitrides and phosphides of the Group IA and IIA metals contain anions of high charge, which behave as strong bases. Therefore, they abstract protons from a variety of proton donors. The following reactions are typical ... 

The nitrides and phosphides of the Group IA and IIA metals are not of great commercial importance. 

Some of the Group IA and IIA metals are found in nature in the form of carbonates, silicates, nitrates, and phosphates. For example, calcium carbonate is one of the most important naturally occurring compounds, and it is found in several forms. The most common form of calcium carbonate is limestone, which is used extensively as a building stone as well as the source of lime. Other forms include chalk, calcite, aragonite, Iceland spar, marble, and onyx. Many other materials such as egg shells, coral, pearls, and seashells are composed predominantly of calcium carbonate. Thus, it is one of the most widely occurring compounds in nature. 

The structures of the organic derivatives of the Group IA and IIA metals are not simple because many of them involve molecular association. For example, the lithium alkyls are tetramers in which the lithium atoms reside at the corners of a tetrahedron and the carbon atoms bonded to them are located above the triangular faces of the tetrahedron as shown in Figure 7.2. 

Solid perxenate (Xe064-) salts can be obtained that contain cations of Group IA and IIA metals. The Xe064- ion has a very weak conjugate acid (HXeOe3-) so the hydrolysis reactions... 

The oxides of the Group IA and IIA metals (the basic oxides, such as Na20, K20, and CaO) also react with acids to form water. These reactions are also neutralization processes that form water. 

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