Naming compounds mono- prefix

Using the same logic, the chemical compound H20 can also be named using the prefixes mono- and di-. Because there is only one oxygen atom in water and the oxygen is the second element in the compound, the prefix mono- is used. The scientific name for H20 is dihydrogen monoxide. Of course, this compound is also much better known by its common name—water. 

Note that the absence of a prefix from the first named element in a molecular compound implies that there s only one atom of that element. In other words, the prefix mono- is unnecessary for the first element only. You still have to attach a mono- prefix, when appropriate, to the names of subsequent elements. 

A. Dinitrogen monoxide, sulfur hexafluoride, and dichlorine octoxide. Notice that none of these compounds contain any metals, which means that they re most certainly molecular compounds. The first compound contains two nitrogen atoms and one oxygen atom, so it s called dinitrogen monoxide. The second compound contains one sulfur and six fluorines. Because sulfur is the first named element, you don t need to include a mono- prefix. You simply name the compound sulfur hexafluoride (rather than monosulfur hexafluoride ). Using the same methods, the third compound is named dichlorine octoxide. 

There are exceptions to using the prefixes shown in Table 8.3. The first element in the compound name never uses the mono- prefix. For example, CO is carbon monoxide, not monocarbon monoxide. Also, if using a prefix results in two consecutive vowels, one of the vowels is usually dropped to avoid an awkward pronunciation. For example, notice that the oxygen atom in CO is called monoxide, not monooxide. 

The same two elements often form more than one binary compound. Their names are distinguished by the prefixes mentioned in the preceding rules. Silicon and chlorine form silicon tetrachloride, SiCl4, and disilicon hexachloride, Si2Clg. The prefix tetra-identifies four chlorine atoms in a molecule of SiC. In Si2Cl6, di- indicates two silicon atoms, and hexa- shows six chlorine atoms in the molecule. Technically, SiC should be monosilicon tetrachloride, but the prefix mono- for one is usually omitted in the first word. If an elemental name has no prefix in a binary molecular compound, you may assume that there is only one atom of that element in the molecule. 

The names of molecular compounds use prefixes because it is possible for atoms of two nonmetals to form two or more different compounds. For example, atoms of carbon and oxygen form carbon monoxide (CO) and carbon dioxide (CO2), in which the number of atoms of oxygen in each compound is indicated by the prefixes mono or di in their names. 

When the vowels 0 and o or a and o appear together, the first vowel is omitted, as in carbon monoxide. In the name of a molecular compound, the prefix mono is usually omitted, as in NO, nitrogen oxide. Traditionally, however, CO is named carbon monoxide. Table 6.12 lists the formulas, names, and commercial uses of some common molecular compounds. 

These examples show that when information is not needed to identify the compound, it is omitted from the name. In the first name, for instance, it is not necessary to tell how many sodium ions are present, because we can deduce the number from the name of the complex anion. In the second name, the oxidation state of zinc is omitted because it is always +2. In the fourth name, the single bromo ligand is not preceded by the prefix mono. 

The final o or a may be dropped if the name of the element begins with a vowel. The prefix mono is being used less often, so you may only see it in a very small number of compounds such as carbon monoxide, CO. 

Figure 12.15 Gangliosides. The prefix mono-, di, tri- or tetra- denotes the number of sialic acid W-acetyl neuraminic acid, NANA) residues present in the molecule. The many different gangliosides have complex structures and for convenience shorthand notations are used. The two commonest were introduced by Svennerholm, who named the parent compound GM1, and Wiegnandt, who named it Ggnti. The latter system gives enough information for the structures to be worked out from the shorthand form once the symbols have been learnt. GalNAc represents N-acetyl galactosamine in the above structure.

Using Table 6-2, translate the subscripts into prefixes. Omit the prefix mono- on the first named element in a compound where applicable. 

GUIDELINE 2 When two or more compounds have different numbers of the same elements, prefixes are added to remove the ambiguity. The first four prefixes are mono- ( one ), di- ( two ), tri- ( three ), and tetra- ( four ). The prefix mono-, however, is commonly omitted from the beginning of the first word of the name ... 

C Covalently bonded substances will use prefixes while ionic compounds will not. Choice A may seem correct, but a covalent compound s name does not start with the prefix mono-. Calcium fluoride is ionic and will not use prefixes at all. Tetra- is correct to indicate four in a covalently bonded compound. P is phosphorus and not potassium. Finally, Ti is titanium and not tin, Sn. 

Such a substance is called an acid salt. The name of the compound includes the word hydrogen to denote the fact that one or more ionizable hydrogen atoms remain. The prefix mono- or di- may be used when it is necessary to indicate how many hydrogen atoms are present ... 

Use Greek prefixes (Table 3.10) to specify the number of atoms of each element in the molecular formula of the compound (di- for two, tri- for three, and so forth). If the compound is a solid without well-defined molecules, name the empirical formula in this way. The prefix for one (mono-) is omitted, except in the case of carbon monoxide. 

The stoichiometric name of the compound is then formed by combining the name of the electropositive constituent, cited first, with that of the electronegative constituent, both suitably qualified by any necessary multiplicative prefixes ( mono , di , tri , tetra , penta , etc., given in Table IV). The multiplicative prefixes precede the names they multiply, and are joined directly to them without spaces or hyphens. The final vowels of multiplicative prefixes should not be elided (although monoxide , rather than monooxide , is an allowed exception because of general usage). The two parts of the name are separated by a space in English. 

Multiplicative prefixes need not be used in binary names if there is no ambiguity about the stoichiometry of the compound (such as in Example 10 above). The prefix mono is, strictly speaking, superfluous and is only needed for emphasizing stoichiometry when discussing compositionally related substances, such as Examples 2, 3 and 4 above. 

Nearly all binary molecular compormds 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. ... 

A few other rules are helpful when naming molecular compounds. If only one atom of the first element is listed, the prefix mono is usually omitted. Also, if the vowel combinations 0-0 or a-o appear next to each other in the name, the first of the pair is omitted to simplify pronunciation. Thus, mononitrogen monooxide, NO, becomes nitrogen monoxide. 

If the subscript for the first element is greater than one, indicate the identity of the subscript using prefixes from Table 3.3. We do not write mono- at the beginning of a compound s name (see Example 3.4). 

When there is more than one possible combination of two elements, the number of atoms of a given type in the compound is designated with a prefix such as mono-, dir, tri-, tetra-, and so on. Table 5.4 lists the prefixes for up to ten atoms, and some common molecular compounds and their names are given in Table 5.5. 

In a binary compound, the element that appears first in the formula also appears first in the name. The first element retains its full name, whereas the second element is described by replacing the ending from its name with the suffix -ide. Both elements will be preceded by a number-designating prefix except that when there is only one atom of the first element, it does not carry the prefix mono-. An example of this procedure is provided in Example Problem 2.5. 

Analogous to the names of molecular compounds, we usually omit the prefix mono- when there is only one H in the anion. 

To name a binary covalent compound, name the first non-metal, including its prefix, then name the second non-metal, using the prefix and changing the ending to ide. (Note the prefix mono is generally not used for the first non-metal in the formula.)... 

Many fluorocarbon compounds are listed by name in the regulations of DOT and TC, and those not listed can be shipped under refrigerant and dispersant gas, n.o.s. entries [9, 10]. At one time, the prefix mono was used in DOT listings to show the presence of one atom of the indicated element, but it is omitted in modem terminology. The prefix mono is not acceptable on documents in Canada. 

The compound NjO, also called laughing gas, is named according to the first element, nitrogen, with the prefix di to indicate that there are two nitrogen atoms and the second element, oxide, with the prefix mono to indicate one oxygen atom. Because mono ends with a vowel and oxide begins with one, the o is dropped on mono and the two are combined as monoxide. The entire name for NjO is as follows ... 

Considering binary molecular compounds, the less electronegative element is named first, without change the more electronegative element is named second, and the ending is changed to —ide. It is also necessary to include the number of atoms in the molecule in the for-mrda name. The only exception here is that if the first element has only one atom, the prefix mono is not used. 

You add a prefix, derived from the Greek, to each element name to denote the subscript of the element in the formula. (The Greek prefixes are listed in Table 2.7.) Generally, the prefix mono- is not used, unless it is needed to distinguish two compounds of the same two elements. 

The prefix mono- is generally omitted for the first element. SO2, for example, is named sulfur dioxide, not monosulfur dioxide. Thus, the absence of a prefix for the first element usually means there is only one atom of that element present in the molecule. In addition, for ease of pronunciation, we usually eliminate the last letter of a prefix that ends in "o or a when naming an oxide. Thus, N2O5 is dinitrogen pentoxide, rather than dinitrogen pentaoxide. Sample Problem 2.4 gives you some practice naming binary molecular compounds from their formulas. 

Historically, the prefix mono was used when only one atom of bromine, chlorine, or sometimes fluorine was present in a compound. At present, the use of mono is optional, and it is omitted from the shipping names in this table. Under the Canadian Transportation of Dangerous Goods Act, use of mono on documents is not acceptable. 

These prefixes and the corresponding number of atoms that they represent are given in Table 3.3. Utilizing this scheme, CO would be named carbon monoxide and CO2 would be named carbon dioxide. Notice in these exan les that the element that is shown first in the formula is also named first. The second word uses the stem of the second nonmetal and the -ide ending, as in the scheme for ionic binary compounds. However, a prefix is placed in front of the stem to indicate the number of atoms of the second nonmetal in the formula (mono- in the case of one atom and di- in the case of two). Actually, a prefix is also used in front of the name of the first element if there is more than one atom of this element indicated in the formula.. For example, the compound N2O is called... 

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