Ionic bonds substances

Water, however, is a wonderful solvent for ionic-bonded substances such as salt. The secret to its success lies in the electric dipoles created by the polar covalent bonds between the hydrogen and oxygen atoms. In water, the polar bonds are asymmetric. The hydrogen side is positive the oxygen side is negative. One measure of the amount of charge separation in a molecule is its dielectric constant. Water has a dielectric constant that is considerably higher than that of any other common liquid. 

The ions that conduct the electrical current can result from a couple of sources. They may result from the dissociation of an ionically bonded substance (a salt). If sodium chloride (NaCl) is dissolved in water, it dissociates into the sodium cation (Na+) and the chloride anion (CL). But certain covalently bonded substances may also produce ions if dissolved in water, a process called ionization. For example, acids, both inorganic and organic, will produce ions when dissolved in water. Some acids, such as hydrochloric acid (HC1), will essentially completely ionize. Others, such as acetic acid (CH3COOH), will only partially ionize. They establish an equilibrium with the ions and the unionized species (see Chapter 13 for more on chemical equilibrium). 

Perhaps the most common example of an ionically bonded substance is NaCl, or table salt. In this, the sodium (Na) atom gives up an electron to the much more electronegative chlorine (Cl) atom, and the two atoms become ions, Na and Cl. The electrostatic bonding force between the two oppositely charged ions extends outside the local area attracting other ions to form giant crystal structures. For this reason most ionically bonded materials are solid at room temperature. 

Ionic bonding was proposed by the German physicist Walther Kossel in 1916 in or der to explain the ability of substances such as molten sodium chloride to conduct an electric current He was the son of Albrecht Kossel winner of the 1910 Nobel Prize in physiology or medi cine for early studies in nu cleic acids... 

Ionic bonds may be fully as strong as covalent bonds, so that properties such as hardness, solubility, melting point, ionization in solution, and chemical character are not especially valuable criteria as a rule. Sometimes comparison of properties with those of compounds of known bond type permits reasonably certain conclusions to be drawn. Thus the similarity in physical properties as well as in atomic arrangement of SiC, AIN, and diamond suggests that all three substances contain covalent bonds. PbS is like FeS2, MoS2, etc. in properties rather than like CaS, so that it is improbable that PbS is an ionic substance. 

After a discussion of the properties of substances containing ionic bonds and electron-pair bonds, it is shown that the transition from one extreme bond type to another could take place continuously in some cases (when... 

In the classroom, ionic bonding is mostly introduced by the example of simple ionic substances like sodium chloride. Starting from the electronic configuration of... 

In pseudoplastic substances shear thinning depends mainly on the particle or molecular orientation or alignement in the direction of flow, this orientation is lost or regained at the same speed. Additionally many dispersions show this potential for particle or molecule interactions, this leads to bonds creating a three-dimensional network structure. They are often build-up from relatively weak hydrogen or ionic bonds. When the network is disturbed. 

Nonmodified silica gel is used most commonly for the separation of substances of medical interest. The separation is based on the interactions (hydrogen bonding, van der Waals forces, and ionic bonding) between the molecules of drugs, lipids, bile acids, etc., and the silica gel. Alumina has similar properties but is rarely used. Successful separation of endogenous substances, drugs, or their metabolites can also be achieved using physically or chemically modified silica gel. 

For each of the substances the possible answers are ionic bonding, covalent bonding, metallic bonding, hydrogen bonding, dipole-dipole force, or London force. Forces, such as ion-dipole forces and ion-induced dipole forces, are not choices because these require the presence of two or more substances. For example, sodium chloride cannot utilize either of these two forces, but sodium chloride in water can. (Sodium chloride in water exhibits ion-dipole forces.)... 

Ionic bonding is present in compounds containing a metal and a nonmetal or in a compound containing one or more polyatomic ions. There are a few exceptions to this generalization, but these usually do not appear in this type of question. An ionic substance must contain at least two different elements, so we... 

One notable chemical interference occurs when atomization is hindered due to an unusually strong ionic bond between the ions in the ionic formula unit. A well-known example occurs in the analysis of a sample for calcium. The presence of sulfate or phosphate in the sample matrix along with the calcium suppresses the reading for calcium because of limited atomization due to the strong ionic bond between calcium and the sulfate and phosphate ions. This results in a low reading for the calcium in the sample in which this interference exists. The usual solution to this problem is to add a substance to the sample that would chemically free the element being analyzed, calcium in our example, from the interference. 

Water is called the universal solvent because of its ability to dissolve at least a little of virtually every substance. Water is a particularly good solvent for substances held together by polar or ionic bonds. Indeed, the most abundant substance dissolved in seawater is an ionic solid, sodium chloride. In comparison, only small amounts of nonpolar substances, such as hydrocarbon oils, will dissolve in water. 

The lattice energy of a crystalline substance U with purely ionic bonds and negligible polarization effects is given by equation 1.68, changed in sign and with the subtraction of an energetic term known as zero-point energy ... 

Many substances contain bonds that are intermediate in character— between pure covalent and pure ionic bonds. Such polar bonds occur when one of the elements attracts the shared electrons more strongly than the other element. In hydrogen fluoride, for instance, the shared electrons are so much more attracted by fluorine than hydrogen that the sharing is unequal. (See Figure 5-11.)... 

When a compound containing ionic bonds is placed in water, the polar water molecules separate some or all of the substance into its cations and anions. The separation is referred to as ionic dissociation. 

Substances that dissociate completely into ions when placed in water are referred to as strong electrolytes because the high ionic concentration allows an electric current to pass through the solution. Most compounds with ionic bonds behave in this manner sodium chloride is an example. 

Stoichiometry. Such a complicated word for such a simple idea. The Greek roots of the word mean measuring elements, which doesn t sound nearly as intimidating. Moreover, the ancient Greeks couldn t tell an ionic bond from an Ionic column, so just how technical and scary could stoichiometry really be Simply stated, stoichiometry is the quantitative relationship between components of chemical substances. In compound formulas and reaction equations, you express stoichiometry by using subscripted numbers and coefficients. 

Final Intermediate The last compound synthesized before the reaction that produces the drug substance. The final step forming the drug substance must involve covalent bond formation or breakage ionic bond fonnation (i.e., making the salt of a compound) does not qualify. Consequently, when the drug substance is a salt, the precursors to the organic acid or base, rather than the acid or base itself, should be considered the final intermediate. 

This difference in bond strength is also responsible for many other differences in the physical properties of these two substances. For instance, whereas the melting point of NaCl is 801°C, that of KCI is only 770°C. The 31°C difference is easy to explain in terms of what happens when a solid-to-liquid phase change occurs the particles of the solid have to be pried apart from one another. The weaker ionic bonds in KCI mean the ions separate more easily, and the macroscopic evidence of this is the lower melting point of KCI. 

The systematic naming of these substances is cumbersome, but they have come to be known as ylides. The genesis of this name may seem obscure, but it is an attempt to reconcile the presence of a C-X a bond, which is covalent and nonpolar as in alky/ derivatives, as well as an ionic bond as in metal h Udes. Hence, the combination yl-ide.2... 

The oppositely charged Na+ and Cl- ions that result when sodium transfers an electron to chlorine are attracted to one another by electrostatic forces, and we say that they are joined by an ionic bond. The crystalline substance that results is said to be an ionic solid. A visible crystal of sodium chloride does not consist of individual pairs of Na+ and Cl- ions, however. Instead, solid NaCl consists of a vast three-dimensional network of ions in which each Na+ is surrounded by and attracted to many Cl - ions, and each Cl- is surrounded by and attracted to many Na+ ions (Figure 6.7). 

Ionic bond The loose linking together of two atoms in a solid substance, where one or more valence electrons are preferentially associated with one of the bonded atoms (compare with covalent bond). 

How do we know that a substance Is held together by ionic bonds ... 

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