Essential descriptive inorganic Chemistry : what every chemistry student should know

Descriptive inorganic chemistry is a big subject. Comprehensive texts (e.g. Comprehensive Inorganic Chemistry) run into several volumes. No student is capable of learning all the facts. Educators have responded to this by arguing that what students need to do is not learn facts but the principles and theories behind the facts. The problem with this approach is that chemical principles and theories are not good enough for this. They only explain a small fraction of all the facts. Teaching principles and theories without any facts therefore leaves students ignorant of many of the facts, including very basic ones. This short text seeks to resolve this problem. It sets out the descriptive inorganic chemistry every chemistry student should know. Only the most important chemistry of the most important elements is included. These are the elements that come high in rankings based on natural abundance, world consumption, and number of compounds.1 Elements are not grouped according to the Periodic Table as this can obscure their distinctive character. Considerations of periodicity complement the material presented here. I have, for the most part, given substances their traditional names. These are the names in, for example, the British National Formulary, used by doctors and pharmacists. In some cases, these differ from the names recommended by the International Union of Pure and Applied Chemistry (IUPAC). In these cases, I also give the IUPAC name. I have followed IUPAC in my spelling of ‘sulfur’. I have also, for the most part, given substances their traditional formulae. Some of these are empirical (e.g. NaCl), some molecular (e.g. HCl), some mixed (e.g. Na2O2). Ideally, these should be differentiated as in, for example, (NaCl), [HCl], and (Na2[O2]), but this is cumbersome. As a general rule, (1) volatile substances are molecular, (2) involatile substances that are soluble in nonionizing volatile solvents are ‘macromolecular’ (i.e. they contain large molecules like C60), and (3) involatile substances that are insoluble in nonionizing volatile solvents are ‘nonmolecular’ (i.e. have a framework structure like diamond or sodium chloride). Types (1) and (2) have molecular formulae, type 3 empirical formulae (or a mixed formula if they contain molecularions).