Nonmetals hydroxide

Francium has many more isotopes (33) than compounds. However, knowing how the other alkali metals form compounds, one may speculate on several possibilities. Its metal ion most likely is Fr, which means it has a very low level of electronegativity and would combine vigorously with anions of nonmetals that have a very high electronegativity. For example, if it reacted with chlorine, it would form FrCl and if a chunk of metallic francium (which would be hard to find) were dropped in water, it would explode and form francium hydroxide (2Fr + 2Up 2FrOH + H t). 

For complete neutralization to take place, the proper amounts of acid and base must be present. The salt formed in the above reaction is NaCl. If the water were evaporated after completing the reaction, we would be left with common table salt. Sodium chloride is just one of hundreds of salts that form during neutralization reactions. While we commonly think of salt, NaCl, as a seasoning for food, in chemistry a salt is any ionic compound containing a metal cation and a nonmetal anion (excluding hydroxide and oxygen). Some examples of salts that result from neutralization reactions include potassium chloride (KCl), calcium fluoride (CaF ), ammonium nitrate (NH NOj), and sodium acetate (NaC2H302). 

Ionic compounds consist of positive ions (cations) and negative ions (anions) hence, ionic compounds often consist of a metal and nonmetal. The electrostatic attraction between a cation and anion results in an ionic bond that results in compound formation. Binary ionic compounds form from two elements. Sodium chloride (NaCl) and sodium fluoride (NaF) are examples of binary ionic compounds. Three elements can form ternary ionic compounds. Ternary compounds result when polyatomic ions such as carbonate (C032 ), hydroxide (OH-), ammonium (NH4+), form compounds. For example, a calcium ion, Ca2+, combines with the carbonate ion to form the ternary ionic compound calcium carbonate, CaC03. Molecular compounds form discrete molecular units and often consist of a combination of two nonmetals. Compounds such as water (H20), carbon dioxide (C02), and nitric oxide (NO) represent simple binary molecular compounds. Ternary molecular compounds contain three elements. Glucose ( 12 ) is a ternary molecular compound. There are several distinct differences between ionic and molecular compounds, as summarized in Table 1.2. 

It is sometimes useful to regard the oxy-acids produced in such hydrolyses as derivatives of nonmetal hydroxides, Thus, phosphorus acid, pro-... 

If the anion is monatomic (has only one atom), the name of the element is amended by changing the ending to -ide. Note that this ending is also used for binary nonmetal-nonmetal compounds. All monatomic anions have names ending in -ide, but there are a few anions that consist of more than one atom which also end in -ide—the most important of these are OH and CN. OH is called the hydroxide ion, and CN is called the cyanide ion. 

Generally liquid ammonia is a good solvent for many salts, such as nitrates, nitrites, iodides, cyanides, thiocyanides, and acetates. Ammonium salts are especially soluble. The hydroxides, fluorides, and salts with di- and trivalent anions, such as oxides and sulfides, in general are insoluble. Apart from alkali metals, some other metals and nonmetals are also soluble. A compilation of the solubilities of organic compounds in liquid ammonia shows notable solubility of saccharoses [1417],... 

Anhydrides Some oxides can become acids or bases by adding the elements contained in water. These compounds are called anhydrides. Oxides of nonmetalUc elements, such as carbon, sulfur, or nitrogen, produce an acid in aqueous solution. Oxides of metallic elements usually form basic solutions. For example, carbon dioxide, an oxide of a nonmetal, forms a solution of carbonic acid, whereas, calcium oxide (CaO) forms a basic solution of calcium hydroxide. 

As pure substances, Group 1A or alkali metals are soft metallic solids with low densities and low melting points. They easily form 1+ cations. They are highly reactive, reacting with most nonmetals to form ionic compounds. Alkali metals react with hydrogen to form hydrides such as NaH. Alkali metals react exothermically with water to produce the metal hydroxide and hydrogen gas. In nature, alkali metals exist only in compounds. 

Table 10-1 contains lists of the common amphoteric hydroxides. Three are hydroxides of metalloids, As, Sb, and Si, which are located along the line that divides metals and nonmetals in the periodic table. 

Unlike nonmetal oxides, which are covalent compounds, metal oxides are ionic compounds. When metal oxides react with water, they produce hydroxide ions. 

The acid strength of nonmetal hydrides increases towards the right and to the bottom of the periodic table. Acid strengths of oxoacids can be predicted approximately from their formulae by Pauling s rules. Metal cations with polarizing character are acidic in water, and some form amphoteric oxides or hydroxides. 

Oxygen forms binary compounds with nearly all elements. Most may be obtained by direct reaction, although other methods (such as the thermal decomposition of carbonates or hydroxides) are sometimes more convenient (see Topic B6). Oxides may be broadly classified as molecular, polymeric or ionic (see Topics B1 and B2). Covalent oxides are formed with nonmetals, and may contain terminal (E=0) or bridging (E-O-E) oxygen. Especially strong double bonds are formed with C, N and S. Bridging is more common with heavier elements and leads to the formation of many polymeric structures such as Si02 (see Topics FT and F4). 

---