Formulas of inorganic compounds

In empirical formulas of inorganic compounds, electropositive elements are listed first [3]. The stoichiometry of the element symbols is indicated at the lower right-hand side by index numbers. If necessary, the charges of ions are placed at the top right-hand side next to the element symbol (e.g., S "). In ions of complexes, the central atom is specified before the ligands are listed in alphabetical order, the complex ion is set in square brackets (e.g., Na2[Sn(OH)+]). 

It is customary in most chemical formulae of inorganic compounds (Chapter 2), to write metallic atoms first (if there are any), e.g. NaCl, sodium chloride, or common salt. In the Periodic Table, the metallic elements extend from the left almost three-quarters of the way across the table all the A groups, groups VIII, IB, IIB and the lower parts of groups IIIB-VIB. In spite of this, the non-metallic elements have the larger role to play in chemistry, as we shall see (Chapters 3-16). 

Names and Formulas of Inorganic Compounds—In this section on the nomenclature of inorganic compounds, the names and formulas of two-element or binary compounds are considered first. The... 

In 1893 Werner founded his new constitutional formula for inorganic compounds, applied the theory to the systematic classification of the chromi-ammines, and found that all the chromi-ammines which had been investigated could be fitted in to his system of classification. Since then the chemistry of the chromi-ammines has been further developed hv Werner, Pfeiffer, and many others relationships have been traced between chromi-ammines, complex salts, and chromic salt hydrates, and numerous cases of isomerism have been discovered in this series of ammines. 

Systematic names and stoichiometric formulae are intended to convey as much information as possible in the smallest space concerning the composition and nature of a substance. The internationally-agreed (though not universally-obeyed) rules for the naming of inorganic compounds are set out briefly in most inorganic texts, and in The Handbook of Chemistry and Physics they need not be repeated here. 

Frankland s45,588-591 research is also a corner stone of organotin chemistry. He favored the valence ideas and the use of modern graphic formulas of organotin compounds. Moreover, his research destroyed the border between inorganic and organic chemistry. 

Inorganic salts of organic acids and inorganic addition compounds of organic compounds (hydrohalides, perchlorates, sulfates, etc.) are not given separate entries but are indicated in modifying phrases under the formula of the compounds from which they are derived (under the acid in the case of a salt). Salts of formic, acetic, and oxalic acids are exceptions these are entered under their own formulas, and lithium acetate is found under C2H3Li02. 

From the dawn of organic chemistry as such to the present time there exists a continuous record in fonnula index form (Table II) of the compounds of this large branch of chemistry. Inorganic chemistry is not so fortunate. [Hoffman (12) indexed organic compounds by formula to 1909.] From this date to 1920, when Chemical Abstracts began indexing by formula, there is no compilation of inorganic compounds by formula. 

So far, we have identified coordination compounds only by their chemical formulas, but names are also useful for many purposes. Some substances were named before their structures were known. Thus, K3[Fe(CN)g] was called potassium fer-ricyanide, and K4[Fe(CN)g] was potassium ferrocyanide [these are complexes of Fe (ferric) and Fe (ferrous) ions, respectively]. These older names are still used conversationally but systematic names are preferred to avoid ambiguity. The definitive source for the naming of inorganic compounds is Nomenclature of Inorganic Chemistry-IUPAC Recommendations 2005 (N. G. Connelly and T. Damhus, Sr., Eds. Royal Society of Chemistry, 2005). 

When atomic theory developed to the point where it was possible to write specific formulae for the various oxides and other binary compounds, names reflecting composition more or less accurately then became common no names reflecting the composition of the oxosalts were ever adopted, however. As the number of inorganic compounds rapidly grew, the essential pattern of nomenclature was little altered until near the end of the 19th century. As a need arose, a name was proposed and nomenclature grew by accretion rather than by systematization. 

An add can be defined as a substance that produces hydrogen ions, H, in aqueous solutions. We usually write the formulas of inorganic acids with hydrogen written first. Organic acids can often be recognized by the presence of the COOH group in the formula. A base is a substance that produces hydroxide ions, OH , in aqueous solutions. A salt is a compound that contains a cation other than H and an anion other than hydroxide ion, OH , or oxide ion, (see Table 2-3 on page 55). As we will see later in this chapter, salts are formed when acids react with bases. 

Oxidation numbers are very useful in correlating and systematizing a lot of inorganic chemistry. A few simple rules allow the prediction of the formulas of covalent compounds, just as predictions were made for ionic compounds in Chapter 4 by using the charges on the ions. 

The common acids are other examples of inorganic compounds that are known by common rather than formal names. Some names of common acids and bases that you will use frequently in chemistry laboratory experiments are listed in Table 5.7. Although they often do not follow the rules you have been learning, they will soon become so familiar that their formulas and names will be easy to remember. 

This is an exercise in writing formulas and naming of inorganic compounds. Complete the following tables. You may use any written material available to assist. The first one is done for you. Your supervisor may ask you to read your table to another technician in the lab to practice pronouncing the names. 

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