Ionic compounds aluminum

An aluminum ion carries a 3+ charge, and an oxide ion carries a 2— charge. Together, these ions make the ionic compound aluminum oxide, AI203, the main component of such gemstones as rubies and sapphires. Figure 6.10 illus-... 

Bromine is one of the two elements that are liquids at room temperature. Mercury is the other. Aluminum is a lightweight metal that resists corrosion. Aluminum and bromine react vigorously to form the ionic compound aluminum bromide. 

Because of iheir relatively large, negative electron affinities, nonmetals tend to gain electrons when they react with metals. For example, the reaction of aluminum with bromine produces the ionic compound aluminum bromide ... 

The oxidation number of an element in a monatomic ion is equal to the charge of that ion. In the ionic compound NaCl, sodium has an oxidation number of +1, chlorine an oxidation number of — 1. The oxidation numbers of aluminum and oxygen in A1203 (Al3+, O2- ions) are +3 and —2, respectively. 

The process for obtaining aluminum from bauxite was worked out in 1886 by Charles Hall (1863-1914), just after he graduated from Oberlin College. The problem that Hall faced was to find a way to electrolyze Al203 at a temperature below its melting point of 2000°C. His general approach was to look for ionic compounds in which Al203 would dissolve at a reasonable temperature. After several unsuccessful attempts, Hall found that cryolite was the... 

Self-Test C.2A Write the formula of the binary ionic compound formed by (a) calcium and chlorine (b) aluminum and oxygen. 

D.12 Write the formula for the ionic compound formed from (a) strontium and bromide ions (b) aluminum and sulfate ions (c) lithium and oxide ions (d) ammonium and sulfide ions ... 

C02-0071. Aluminum is one of the few elements that forms cations with +3 charge. What are the chemical formulas of the ionic compounds that form between aluminum and (a) oxygen (b) fluorine ... 

Many ionic compounds can have water molecules incorporated into their solid structures. Such compounds are called hydrates. To emphasize the presence of discrete water molecules in the chemical structure, the formula of any hydrate shows the waters of hydration separated from the rest of the chemical formula by a dot. A coefficient before H2 O indicates the number of water molecules in the formula. Copper(II) sulfate pentahydrate is a good example. The formula of this beautiful deep blue solid is C11SO4 5 H2 O, indicating that five water molecules are associated with each CuSOq unit. Upon prolonged heating, CuSOq 5 H2 O loses its waters of hydration along with its color. Other examples of hydrates include aluminum nitrate nonahydrate, A1 (N03)3 9 H2 O,... 

Other metallic elements form ionic compounds with cation charges ranging from -F1 to + 3. Aluminum nitrate nonahydrate, A1 (N03)3 9 H2 O, is composed of cations, NO3 anions, and water molecules. Silver nitrate (AgNO ), which contains Ag cations, is a soluble silver salt that is used in silver plating. 

The compound is ionic — a metal (Al) bonded to a nonmetal (Cl). All ionic compounds are solids at room temperature and pressure. Aluminum has 13 electrons. As an ion, it will lose 3 electrons to become isoelectronic with neon. Thus the aluminum ion will have the electronic configuration ls22s22p6. 

Another way of deriving the formula of the ionic compound is the crisscross rule. In this technique the cation and anion are written side by side. The numerical value of the superscript charge on the cation (without the sign) becomes the subscript on the nonmetal in the compound, and the superscript charge on the anion becomes the subscript on the metal in the compound. Figure 11.3 illustrates the crisscross rule for the reaction between aluminum and oxygen. 

Water, alcohols, ethers, or amines can cause inhibition of ionic polymerization. However, these substances can act in different ways according to their concentration. For example, in polymerizations initiated by Lewis acids (BF3 with isobutylene) or organometallic compounds (aluminum alkyls), water in small concentrations behaves as a cocatalyst, but in larger concentrations as an inhibitor (reaction with the initiator or with the ionic propagating species). 

The meso-ionic l,2,4-triazol-3-ones (200) are stable to acid, but alkaline hydrolysis gives 1,4-disubstituted semicarbazides. They do not normally participate in 1,3-dipolar cycloadditions, but the meso-ionic 1,4-diphenyl-l,2,4-triazol-3-one (200, R = R = Ph, R = H) and benzyne yielded 2-phenylindazole. 1,2,4-Triazolium salts (211) are formed with triethyloxonium tetrafluoroborate. Reduction of the meso-ionic compound 200, R = Me, R = R = Ph, with lithium aluminum hydride gives the triazolidinone 212. ... 

Polar framework compounds. These are compounds where no individual molecules exist, and range from ionic compounds like sodium chloride, through part-ionic, part-covalent compounds like aluminum oxide, to polar covalent framework solids like silicon dioxide. 

An ionic compound typically contains a multitude of ions grouped together in a highly ordered three-dimensional array. In sodium chloride, for example, each sodium ion is surrounded by six chloride ions and each chloride ion is surrounded by six sodium ions (Figure 6.11). Overall there is one sodium ion for each chloride ion, but there are no identifiable sodium-chloride pairs. Such an orderly array of ions is known as an ionic crystal. On the atomic level, the crystalline structure of sodium chloride is cubic, which is why macroscopic crystals of table salt are also cubic. Smash a large cubic sodium chloride crystal with a hammer, and what do you get Smaller cubic sodium chloride crystals Similarly, the crystalline structures of other ionic compounds, such as calcium fluoride and aluminum oxide, are a consequence of how the ions pack together. 

Write the formulas for the following ionic compounds (a) barium oxide (b) aluminum chloride (c) magnesium phosphate. 

What about when the ionic charges aren t equal to each other The most mathematically sophisticated way to determine this ratio is to seek the least common multiple between the absolute values of the charges on the cation and anion. Most beginning students, however, simply use the criss-cross method, as shown in Figure 2.9. That is, the number of cations in the formula is the absolute value of the charge on the anion. The number of anions in the formula is the absolute value of the charge on the cation. For example, as shown above, the formula of the ionic compound containing aluminum ions and oxide ions is... 

Sewage treatment has both ecological and economical importance. Ammonium and phosphate ions are the primary inorganic contaminants in municipal wastewater and these ionic compounds are responsible for the phenomenon of eutrophication. In common sewage treatment, ammonium is removed by biological denitrification and phosphates are precipitated with the help of aluminum and iron salts [56], However, the use of low-cost natural zeolites has been found promising for... 

The compounds, silver imide and aluminum nitride, are largely covalent but hydrolysis of either yields ammonia, just as do the hydrolyses of the ionic compounds sodamide or magnesium nitride thus none of these compounds is stable in the presence of moisture. Since water is a stronger... 

Light metals have low densities (< 3 g cm-3) and occur in nature mainly as ionic compounds (e.g., Na+ and Ca2+) associated with Cl, S04, CGj, P04 , NOj and so on. Aluminum is commonly associated with the oxide ion O2- (e.g., soil minerals). Light metals are used in industrial applications and some serve as nutrients to various organisms and higher plants. Additional information on light metals is given in Table 1.3. 

F, T The correct name of this compound is aluminum chloride. Prefixes are not used when naming ionic compounds. Prefixes are used when naming covalent compounds. 

In Chapter 5, we learned to write formulas for ionic compounds from the charges on the ions and to recognize the ions from the formulas of the compounds. For example, we know that aluminum chloride is AICI3 and that VCI2 contains ions. We cannot make comparable deductions for covalent compounds because they have no ions there are no charges to balance. To make similar predictions for species with covalent bonds, we need to use the concept of oxidation number, also called oxidation state. A system with some arbitrary rules allows us to predict formulas for covalent compounds from the positions of the elements in the periodic table and also to balance equations for complicated oxidation-reduction reactions. 

The high abundance of aluminum has resulted in a multitude of apphcations for the element and its compounds. Aluminum derives its name from alum, the double sulfate KA1(S04)2-12H20, which was used medicinally as an astringent in ancient Greece and Rome. Today, aluminum plays an important role as the pure metal and its alloys while its compounds have extensive applications as structural and medical ceramics, electronic and optical materials, catalysts, ionic conductors, coagulants for water purification, and reagents for preparation of other chemicals. " ... 

An operational description is that one reactant (the more ionic compound with the more electropositive metal) transfers alkyl anions to the other. Thus the four methyl groups in Li2BeMe4 form a distorted tetrahedron around the beryllium, with longer distances to the lithium ions. However, this description is oversimplified. The low-temperature nuclear magnetic resonance (NMR) spectrum of Li3MgMe5 has three different methyl resonances, suggesting structure (14), related to the MeLi tetramer. Ate complexes with zinc and aluminum compounds also form. Electron-deficient bridge-bonded structures, exemplified by the X-ray structure of... 

Note that the use of a Roman numeral in a systematic name is required only in cases in which more than one ionic compound forms between a given pair of elements. This case most commonly occurs for compounds containing transition metals, which often form more than one cation. Elements that form only one cation do not need to be identified by a Roman numeral. Common metals that do not require Roman numerals are the Group 1A elements, which form only 1+ ions the Group 2A elements, which form only 2+ ions and aluminum, which forms only Al3+. Common transition metals that do not require a Roman numeral (because they form only one ion) are zinc (Zn2+) and silver (Ag+). 

When aluminum metal is heated with an element from Group 6A of the periodic table, an ionic compound forms. When the experiment is performed with an unknown Group 6A element, the product is 18.56% A1 by mass. What is the formula of the compound ... 

A third plating bath is based on the use of A1 Br and KBr in toluene, ethylbenzene, or similar aromatic solvents. The chlorides and bromides of aluminum are covalent compounds and are highly soluble in aromatic hydrocarbons. An ionic compound such as KBr is not soluble in an aromatic hydrocarbon but is readily dissolved in a solution containing A1 Br, forming a compound according to the equation... 

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