Suffixes molecular compounds

Prefixes precede each element to indicate the number of atoms in the molecular compound. The stem of the second element is used with the ide suffix. The prefix mon is dropped for the initial element, that is, if no prefix is given, it is assumed the prefix is one. Examples of molecular com-... 

You can attach the prefixes in Table 6-2 to any of the elements in a molecular compound, as exemplified by SO3 (sulfur trioxide) and N2O (dinitrogen monoxide). The second element in each compound receives the -ide suffix, as in ionic compounds (which we discuss earlier in this chapter). In the case of molecular compounds, where cations or anions aren t involved, the more electronegative element (in other words, the element that s closer to the upper right-hand corner of the periodic table) tends to be named second. 

Molecular compounds (compounds making up molecules with a neutral charge) are usually composed entirely of nonmetals and are named by placing the less electronegative atom first. See Skill 3.3 for the relationship between electronegativity and the periodic table. The suffix -ide is added to the second, more electronegative atom, and prefixes indicating numbers are added to one or both names if needed. 

For binary molecular compounds (compounds with only two elements), the name begins with the name of the element that is farthest to the left and lowest in the periodic table. The name of the second element is given the suffix -ide and a Greek number prefix is used on the first element if necessary (e.g., dinitrogen tetroxide, N204). 

Nearly all binary molecular compounds involve two nonmetals bonded together. Although many nonmetals can exhibit different oxidation numbers, their oxidation numbers are not properly indicated by Roman numerals or suffixes. Instead, elemental proportions in binary covalent compounds are indicated by using a prefix system for both elements. The Greek and Latin prefixes for one through ten are mono, di, tri, tetra, penta, hexa, hepta, octa, nona, and deca. The prefix mono- is omitted for both elements except in the common name for CO, carbon monoxide. We use the minimum number of prefixes needed to name a compound unambiguously. The final a in a prefix is omitted when the nonmetal stem begins with the letter o we write heptoxide, not heptaoxide. ... 

With molecular compounds, we never (and I really do mean never) use the ous-ic or ite-ate suffixes, or the Roman numerals. Instead, we use the following Greek prefixes to indicate numbers of atoms ... 

Boron Compounds. Molecular hydrides of boron are called boranes. They are named by using a multiplying affix to designate the number of boron atoms and adding an Arabic numeral within parentheses as a suffix to denote the number of hydrogen atoms present. Examples are pentaborane(9) for B5H9 and pentaborane(ll) for B5Hn. 

Ketones have the carbonyl group attached to an interior carbon atom of an organic compound. The carbonyl group gives the molecular polarity, thus many ketones are used as solvents. In the naming of ketones, you need to replace the ending of the molecule with the suffix -one. A number is used to indicate the position of the carbonyl group in the molecule. 

The root and the suffix of an alkane name do not tell you directly about the number of hydrogen atoms in the compound. If you did not know the molecular formula of heptane, for example, how would you still know that heptane contains 16 hydrogen atoms ... 

The first thing that you want to do is determine the molecular formula for the compound. The prefix prop- tells us (see Figure 4 fh) that we are dealing with a compound that contains three carbon atoms. The suffix -ene tells us that we are dealing with an alkene. Alkenes contain twice as many hydrogen atoms as carbon atoms, so propene must have six hydrogen atoms (2x3 = 6). 

Binary compounds consist of two elements they may be either ionic or molecular. The rule is to name the more metallic element first and the less metallic element second. The less metallic element is named by adding an -ide suffix to the element s unambiguous stem. Stems for the nonmetals follow. 

Chemical formulas describe the simplest atom ratio (empirical formula), actual atom number (molecular formula), and atom arrangement (structural formula) of one unit of a compound. An ionic compound is named with cation first and anion second. For metals that can form more than one ion, the charge is shown with a Roman numeral. Oxoanions have suffixes, and sometimes prefixes, attached to the element root name to indicate the number of oxygen atoms. Names of hydrates give the number of associated water molecules with a numerical prefix. Acid names are based on anion names. Covalent compounds have the first word of the name for the element that is leftmost or lower down in the periodic table, and prefixes show the number of each atom. The molecular (or formula) mass of a compound is the sum of the atomic masses in the formula. Molecules are depicted by various types of formulas and models. 

Because the skeleton immediately preceding the compound number 1004 description lacks double bonds, it is necessary to include in the molecular description the steric relationships about each of the three double bonds. The first double bond occurs at C-2-C-3 and according to sequence-rule-preference, the Z suffix stipulates that C-1 and C-4 occur on the same side of the double bond. The Z suffix of the C-6-C-7 double bond requires that the two... 

The names and condensed structural formulas of 20 normal alkanes are given in Table 4.1. The first four compounds have common names. The names of the higher-molecular-weight compounds are derived from Greek numbers that indicate the number of carbon atoms in the chain. Each name has the suffix -ane, which identifies the compound as an alkane. 

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