Naming compounds containing only nonmetals

Some compounds, namely molecular compounds, contain only nonmetals. Normally the compounds you need to name are binary compounds (containing only two elements). If you have highlighted the metalloids on your periodic table, everything to the right of the metalloids is a nonmetal. The following rules apply to both nonmetals and metalloids. The only nonmetal excluded from these nomenclature rules is hydrogen. 

To write the formula from the name of a binary compound containing only nonmetals, simply write the symbols for the separate atoms with the prefixes converted to subscripts. 

To learn to name binary compounds containing only nonmetals... 

Binary compounds that contain only nonmetals are named in accordance with a system similar in some ways to the rules for naming binary ionic compounds, but there are important differences. Type HI binary compounds contain only nonmetals. The following rules cover the naming of these compounds. 

Binary compounds can be named systematically by following a set of relatively simple rules. For compounds containing both a metal and a nonmetal, the metal is always named first, followed by a name derived from the root name for the nonmetal. For compounds containing a metal that can form more than one cation (Type 11), we use a Roman numeral to specify the cation s charge. In binary compounds containing only nonmetals (Type 111), prefixes are used to specify the numbers of atoms. 

Plan Each of the compounds contains only two elements, so to find the formula, we find the simplest whole-number ratio of one atom to the other. Then we determine the name (see Sample Problems 2.5, 2.6, and 2.11) and the mass (see Sample Problem 2.13). Solution (a) There is one brown (sodium) for each green (fluorine), so the formula is NaF. A metal and nonmetal form an ionic compound, in which the metal is named first sodium fluoride. 

B. Naming Binary Compounds That Contain Only Nonmetals (Type III)... 

Name each of the following binary compounds, using the periodic table to determine whether the compound is likely to be ionic (containing a metal and a nonmetal) or nonionic (containing only nonmetals). 

What about covalent compounds Covalent compounds are nonicmic, molecular compounds. For the most part, they contain only nonmetal atoms. A huge number of such compounds exist, and the naming schemes for these are much more involved than what we have seen for ionic compounds. The schemes we will study in this chapter are limited to compounds that contain only two nonmetals and compounds that are acids. Compounds, whether ionic or covalent, that contain just two elements are called binary compounds. Compounds, whether ionic or covalent, that contain three elements are called ternary compounds. The naming scheme for binary covalent compounds is discussed in Section 3.7. The naming scheme for acids, both binary and ternary, is discussed in Section 3.8. 

Many hydrogen compounds are acids. Acids require a different system of nomenclature than other compounds. There are two types of acids binary acids and ternary acids. All acids include the word acid in their name. Binary acids contain only two elements one of which is hydrogen and the other a nonmetal. When naming binary acids, the prefix hydro- appears before the root name of the nonmetal, and there will be an -ic suffix. As an acid, H2S would be hydrosulfuric acid. We used H2S to illustrate the fact that there can be two possible names, hydrogen sulfide or hydrosulfuric acid. If your instructor does not specify which name to use, either is correct. Technically, the name hydrosulfuric acid only applies to aqueous solutions of H2S, H2S(aq). 

The rules for naming chemical compounds depend on whether the substance is a molecular substance or an ionic substance. Molecular compounds are comprised only of nonmetals. Ionic compounds are almost always comprised of a metal and a nonmetal. If a compound contains one of the polyatomic ions listed in Table 2.1, it is an ionic compound. 

The rules for naming binary compounds are summarized in Fig. 2.22. Notice that prefixes to indicate the number of atoms are used only in Type III binary compounds (those containing two nonmetals). An overall strategy for naming compounds is summarized in Fig. 2.23. 

The anesthetic dinitrogen oxide (N2O), commonly known as nitrous oxide, is a covalently bonded compound. Because it contains only two different elements, it is a binary molecular compound. Binary molecular compounds are composed of two different nonmetals and do not contain metals or ions. Although many of these compounds have common names, they also have scientific names that reveal their composition. Use the following simple rules to name binary molecular compounds. 

The preceding method is sufficient for naming binary ionic compounds containing metals that exhibit only one oxidation number other than zero (Section 4-4). Most transition metals and the metals of Groups IIIA (except Al), IVA, and VA, exhibit more than one oxidation number. These metals may form two or more binary compounds with the same nonmetal. Ta distinguish among all the possibilities, the oxidation number of the metal is indicated by a Roman numeral in parentheses following its name. This method can be applied to any binary compound of a metal and a nonmetal. 

You are given the formula for a compound. The formula contains the elements and the number of atoms of each element in one molecule of the compound. Because only two different elements are present and both are nonmetals, the compound can be named using the rules for naming binary molecular compounds. 

Name five metals and five nonmetals that are very likely to form ionic compounds. Write formulas for compounds that might result from the combination of these metals and nonmetals. Name these compounds. Name one ionic compound that contains only non-metallic elements. 

For an ionic compound, you must next decide whether the metal forms only one type of ion or more than one type of ion. Group lA (alkali) mefals. Group 2A (alkaline earth) metals, and aluminum will always form only one type of ion (Figure 4.14). Most of the transition metals will form more fhan one type of ion. Once you have identified the type of ionic compound, name if according to fhe scheme in fhe chart. If the ionic compound contains a polyatomic ion—something you must learn to recognize by familiarity—insert the name of the polyatomic ion in place of the metal (positive polyatomic ion) or the nonmetal (negative polyatomic ion). 

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