Charge neutralization Chlorine

The ion Fe2+ is converted into ion Fe3+ (oxidation), and the neutral chlorine molecule into negatively charged chloride ions Cl" (reduction) the conversion of Fez+ into Fe3+ requires the loss of one electron, and the transformation of the neutral chlorine molecule into chloride ions necessitates the gain of two electrons. This leads to the view that, for reactions in solutions, oxidation is a process involving a loss of electrons, as in... 

In living systems, chlorine is present as chloride, Cl . In part, chloride is there to balance ont the charges contributed by cations such as sodium and potassium ions. There are mechanisms to get chloride across biological membranes as required to maintain charge neutrality. When such a mechanism goes wrong, it is a problem. 

Each electrically neutral chlorine molecule changes to two negatively charged ions. Each of these atoms gains an electron and is therefore reduced ... 

It is not always obvious from the charges alone whether a substance is undergoing oxidation, reduction, or neither process. For example, MnC>2 reacts with hydrochloric acid to produce, among other things, the Mn2+ ion and chlorine gas, CI2. The neutral chlorine, CI2, is produced from the chloride ion, Cl-, which is an oxidation (2C1- CI2). However, since manganese has a charge in both cases, MnC>2 and Mn2+, it would be easy to... 

During the electrolysis of a solution of zinc chloride, both of the ions of the solute (i.e., Zn2+ and Cl ) have their ionic charges neutralized at the cathode and anode, respectively. These ions may therefore be said to have been discharged and liberated in the form of elemental zinc and chlorine. To determine whether the ions corresponding to the solute are always discharged at the electrodes during electrolysis, it is necessary to inquire into the behavior of other electrolytes. 

Figure 3 Energy versus charge for chlorine (solid line) and sodium (dashed line). The lines are a quadratic fit through the energies of the ions relative to the neutral atom.

For example, sodium metal contains neutral sodium atoms, and chlorine gas is made up of CI2 molecules, each of which contains two neutral chlorine atoms. Therefore, an atom in a pure element has no charge and is assigned an oxidation state of zero. 

A second type of chemical bond results from attractions among ions. An ion is an atom or group of atoms that has a net positive or negative charge. The best-known ionic compound is common table salt, or sodium chloride, which forms when neutral chlorine and sodium react. 

Now consider the chlorine atom in sodium chloride. The neutral chlorine atom has acquired a negative charge by gaining an electron. Because it has unequal numbers of protons and electrons, it s now an ion, represented like... 

A great deal of chemical activity involves the transfer of electrons between substances. Ions form when one or more electrons transfer from one neutral atom to another. Figure 2.23 A shows that when elemental sodium is allowed to react with elemental chlorine, an electron transfers from a neutral sodium atom to a neutral chlorine atom. We are left with an Na ion and a Q ion. Objects of opposite charge attract, however, so the Na" and the CF ions bind together to form the compound sodium chloride (NaQ), which we know better as common table salt. Sodium chloride is an example of an ionic compound, a compound that contains both positively and negatively charged ions. 

In brief, the reason that NQI parameters are so useful is because the tenets of molecular structure and reactivity that are used to describe chemistry are based on models that describe an arrangement of atoms subject to character in the sense that some constituents are charged, neutral, or in some way polarized. For example, chlorine-containing molecules are useful subjects for testing the correlation between nuclear quadrupole interaction parameters and bond properties because both extremes of bond character are easily measured a purely ionic character assigned to chlorine would yield a nearly complete shell associated with chlorine and no nuclear quadrupole coupling, whereas a covalent bond, such as that of CI2, would... 

Since ionic compounds are charge-neutral, and since many elements form only one type of ion with a predictable charge, we can deduce the formulas for many ionic compounds from their constituent elements. For example, the formula for the ionic compound composed of sodium and chlorine must be NaCl because in compounds Na always forms Ideations and Cl always forms 1— anions, hi order for the compound to be charge-neutral, it must contain one Na cation to every one CF anion. The formula for the ionic compound composed of calcium and chlorine, however, is CaCl2 because Ca always forms 2+ cations and Cl always forms 1— anions. In order for this compound to be charge-neutral, it must contain one Ca cation for every two CF anions. 

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