应用化学专业英语unit 7.ppt

The Nomenclature of Inorganic Substance;You will meet compounds in this text and will learn their name as you go along. ;However, it is useful from the outset to know something about how to form their names. ;Many compounds were given common names before their compositions were known. Common names include water, salt, sugar, ammonia, and quartz. ;A systematic name, on the other hand, reveals which elements are present and, in some cases, how their atoms are arranged.;The systematic name of table salt, for instance, is sodium chloride, which indicates at once that it is a compound of sodium and chlorine. ;The systematic naming of compounds, which is called chemical nomenclature, follows a set of rules, so that the name of each compound need not be memorized, only the rules. ;Names of Cations;When an element can form more than one kind of cation, such as Cu+ and Cu2+ from copper, we use the Stock number, a Roman numeral equal to the charge of the cation. ;Thus, Cu+ is a copper (Ⅰ) ion and Cu2+ is a copper (Ⅱ) ion. Similarly, Fe2+ is an iron (Ⅱ) ion and Fe3+ is an iron (Ⅲ) ion. ;Most transition metals form more than one kind of ion, so it is usually necessary to include a Stock number in the names of their compounds.;An older system of nomenclature is still in use. ;For example, some cations were once denoted by the endings –ous and –ic for the ions with lower and higher charges, respectively. ;In this system, iron (Ⅱ) ions are called ferrous ions and iron (Ⅲ) ions are called ferric ions. ;Names of Anions;There is no need to give the charge, because most elements that form monatomic anions form only one kind of ion. ; The ions formed by the halogens are collectively called halide ions and include fluoride (F-), chloride (Cl-), bromide (Br-), and iodide ions (I-). ;The names of oxoanions are formed by adding the suffix –ate to the stem of the name of the element that is not oxygen, as in the carbonate ion, CO32-. ;However, many elements can form