Ionic compounds characteristics

It is soluble in organic solvents (a characteristic of a covalent compound). but dissolves in water and can form hydrates (a characteristic of an ionic compound), hence the hydrated must be... 

Elements at the right of the p block have characteristically high electron affinities they tend to gain electrons to complete closed shells. Except for the metalloids tellurium and polonium, the members of Groups 16/VI and 17/VII are nonmetals (Fig. 1.62). They typically form molecular compounds with one another. They react with metals to form the anions in ionic compounds, and hence many of the minerals that surround us, such as limestone and granite, contain anions formed from non-metals, such as S2-, CO,2-, and S042-. Much of the metals industry is concerned with the problem of extracting metals from their combinations with nonmetals. 

The nature of a binary hydride is related to the characteristics of the element bonded to hydrogen (Fig. 14.8). Strongly electropositive metallic elements form ionic compounds with hydrogen in which the latter is present as a hydride ion, H. These ionic compounds are called saline hydrides (or saltlike hydrides). They are formed by all members of the s block, with the exception of beryllium, and are made by heating the metal in hydrogen ... 

Recognizing Cause and Effect In a crystal lattice structure, the electrons are held tightly by the ions, which are rigidly held in place by electrostatic attraction. Discuss how this characteristic explains why ionic compounds generally (a) have high melting points and (b) do not conduct electricity in the solid state. 

Now that we know how to name the cations and anions, we merely have to put the two names together to get the names of ionic compounds. The cation is named first and the anion is named next. The number of cations and anions per formula unit need not be included in the name of the compound because anions have characteristic charges, and the charge on the cation has already been established by its name. There are as many cations and anions as needed to get a neutral compound with the lowest possible subscripts. 

When a substance made up of ions is dissolved in water, the dissolved ions behave independently. That is, they undergo their own characteristic reactions regardless of what other ions may be present. For example, barium ions in solution, Ba2, always react with sulfate ions in solution, S04 , to form an insoluble ionic compound, BaS04(s), no matter what other ions are present in the barium solution. If a solution of barium chloride, BaCK, and a solution of sodium sulfate, Na S04, arc mixed, a white solid, barium sulfate, is produced. The solid can be separated from the solution by filtration, and the resulting solution contains sodium chloride, just as it would if solid NaCl were added to water. In other words, when the two solutions are mixed, the following reaction occurs ... 

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. 

One hundred and forty-four meso-ionic heterocycles of type A (13, 19) and 84 meso-ionic heterocycles of type B (14, 20) are possible. The numbers of these two types which are now known (Table I type A, 44 representatives) and (Table II type B, 8 representatives) encourage us to put forward the proposal that the term meso-ionic should in future be restricted to five-membered heterocycles belonging to type A (13, 19) and type B (14,20). This clear restriction upon the use of the term meso-ionic has obvious advantages. It still embraces 228 different classes of heterocycles with a common structural characteristic, and the many types of meso-ionic compounds included in the authoritative review by Ohta and Kato " are included. Needless to say, the restriction upon the definition of the term meso-ionic to five-mem red heterocycles of type A and type B still includes, for example, benz derivatives such as the compounds 67, 71, 110, 123, 133, 151, 206, 209, 226, 255, and 258. 

As the valency of the metal increases, the bonding in these simple binary compounds becomes more covalent and the highly symmetrical structures characteristic of the simple ionic compounds occur far less frequently, with molecular and layer structures being common. Many thousands of inorganic crystal structures exist, ffere we describe just a few of those that are commonly encountered and those that occur in later chapters. 

Each pure element forms a crystalline solid when it freezes. In these crystals, the atoms of the elements are stacked in regular arrays that form a pattern characteristic of the particular element. Molecular compounds (such as carbon dioxide, water, and glucose) and metal alloys (such as brass) are also crystalline. Ionic compounds (such as sodium chloride and... 

Only the Fluorides have structures and properties expected for ionic compounds with cations of the appropriate size (ZnF2 rutile, the others fluorite). In other compounds, the characteristic coordination... 

For example, hydrogen chloride, also known as hydrochloric acid, has a low melting point and a low boiling point. (It is a gas at room temperature.) These properties might lead you to believe that hydrogen chloride is a covalent compound. Hydrogen chloride, however, is extremely soluble in water, and the water solution conducts electricity. These properties are characteristic of an ionic compound. Is there a clear, theoretical way to decide whether the bond between hydrogen and chlorine is ionic or covalent The answer lies in a periodic trend. 

In section 3.1, you reviewed your understanding of the physical properties of covalent and ionic compounds. You learned how to distinguish between an ionic bond and a covalent bond based on the difference between the electronegativities of the atoms. By considering what happens to electrons when atoms form bonds, you will be able to explain some of the characteristic properties of ionic and covalent compounds. 

Ionic compounds and covalent compounds have characteristic properties. You can use these properties to classify various compounds. 

Name three characteristics of covalent compounds and three characteristics of ionic compounds. 

Because the ions are strongly held around each other, they attract each other in all directions over the surface of the ions. Thus there are no characteristic bond angles in ionic compounds (cf. the specific bond angles in a covalent molecule). Ionic crystals are large collections of ions held together in an ordered pattern to form characteristic crystal shapes. Sodium chloride is a cubic crystal, other compounds also have shapes such as pyramids or distorted cubes, depending upon the size of the individual ions. 

The ionic defects characteristic of the fluorite lattice are interstitial anions and anion vacancies, and the actinide dioxides provide examples. Thermodynamic data for the uranium oxides show wide ranges of nonstoichiometry at high temperatures and the formation of ordered compounds at low temperatures. Analogous ordered structures are found in the Pa-O system, but not in the Np-O or Pu-O systems. Nonstoichiometric compounds exist between Pu02 and Pu016 at high temperatures, but no intermediate compounds exist at room temperature. The interaction of defects with each other and with metallic ions in the lattice is discussed. 

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