Condensed structural formulas table

Condensed structural formulas (Table 1-2) are written without showing all the individual bonds. In a condensed structural formula, each central atom is shown together with the atoms that are bonded to it. The atoms bonded to a central atom are often listed after the central atom (as in CH3CH3 rather than H3C—CH3) even if that is not their actual bonding order. In many cases, if there are two or more identical groups, parentheses and a subscript may be used to represent all the identical groups. Nonbonding electrons are rarely shown in condensed structural formulas. 

Molecular formulas merely include the kinds of atoms and the number of each in a molecule (as C4H , for butane). Structural formulas show the arrangement of atoms in a molecule (see Fig. 1-1). When unshared electrons are included, the latter are called Lewis (electron-dot) structures [see Fig. 1-1(/)]. Covalences of the common elements—the numbers of covalent bonds they usually form—are given in Table 1-1 these help us to write Lewis structures. Multicovalent elements such as C, O. and N may have multiple bonds, as shown in Table 1-2. In condensed structural formulas all H s and branched groups are written immediately after the C atom to which they are attached. Thus the condensed formula for isobutane [Fig. l-l(f>)) is CH,CH(CH,)... 

SAMPLE SOLUTION (a) Note in Table 2.2 that hentriacontane has 31 carbon atoms. All the alkanes in Table 2.2 have unbranched carbon chains. Hentriacon- tane has the condensed structural formula CH3(CH2)29CH3. ... 

When a condensed structural formula is written for a compound containing double or triple bonds, the multiple bonds are often drawn as they would be in a Lewis structure. Table 1-3 shows examples of condensed structural formulas containing multiple bonds. Notice that the —CHO group of an aldehyde and the —COOH group of a carboxylic acid are actually bonded differently from what the condensed notation suggests. Condensed structures are assumed to follow the octet rule even if the condensed notation does not show the bonding. 

As you can see from Tables 1-2 and 1-3, the distinction between a complete Lewis structural formula and a condensed structural formula can be blurry. Chemists often draw formulas with some parts condensed and other parts completely drawn out. You should work with these different types of formulas so that you understand what all of them mean. 

TABLE 1-3 Condensed Structural Formulas for Double andTriple Bonds ... 

In Table 22-1, you can see that the structural formulas are written in a different way from those in Figure 22-3. These formulas, called condensed structural formulas, save space by not showing how the hydrogen atoms branch off the carbon atoms. Condensed formulas can be written in several ways. In Table 22-1, the fines between carbon atoms have been eliminated to save space. 

In Table 21.2, you can see that -CH2- is a repeating unit in the chain of carbon atoms. Note, for example, that pentane has one more -CH2- unit than butane. You can further condense structural formulas by writing the -CH2- unit in parentheses followed by a subscript to show the number of units, as is done with octane, nonane, and decane. 

The formulas for the alkanes given in Table 24.2 are written in a notation called condensed structural formulas. This notation reveals the way in which atoms are bonded to one another but does not require drawing in all the bonds. For example, the structural formula and the condensed structural formulas for butane (C4H10) are... 

TABLE 24.4 - Condensed Structural Formulas and Common Names for Several Alkyl Groups... 

In Table 1.2, we have used both expanded and condensed structural formulas for the compounds. Expanded structural formulas show all covalent bonds, whereas condensed structural formulas show only specific bonds. You should become familiar with both types, but especially with condensed formulas because they will be used often. 

All the alkanes in Table 2.2 have unbranched carbon chains. Hentriacontane has the condensed structural formula CH3(CH2)29CH3. 

TABLE Names, Molecular Formulas, and Condensed Structural Formulas 1 for the First 20 Alkanes with Unbranched Chains ... 

The first four prefixes listed in Table 3.2 were chosen by the lUPAC because they were well established in the language of organic chemistry. In fact, they were well established even before there were hints of the structural theory underlying the discipline. For example, the prefix but- appears in the name butyric acid, a compound of four carbon atoms formed by the air oxidation of butter fat (Latin butyrum, butter). Prefixes to show five or more carbons are derived from Greek or Latin numbers. (See Table 3.1 for the names, molecular formulas, and condensed structural formulas for the first 20 alkanes with unbranched chains.)... 

We will frequently use either Lewis structures or condensed structural formulas to represent organic compounds. Notice that each carbon atom in an alkane has four single bonds, whereas each hydrogen atom forms one single bond. Notice also that each succeeding compound in the series listed in Table 25.1 has an additional CH2 unit. 

The alkanes in Table 6-2 are each represented with a molecular formula, a structural formula, and a condensed structural formula. Note that a condensed structural formula, such as CHgCHjCHj, does not mean C—— C——C—but instead represents the following structure ... 

The smaller alkanes from 1-4 carbon atoms are gases at room temperature and used as heating fuels. The alkanes with 5-8 carbon atoms are liquids at room temperature and found in fuels such as gasoline. The molecular formula gives the total number of each kind of atom, but does not indicate the arrangement of the atoms in the molecule. Table 17.2 shows the molecular, expanded, and condensed structural formulas for alkanes with one, two, and three carbon atoms. 

TABLE 17.6 lUPAC and Common Names of Selected Carboxylic Acids Condensed Structural Formula lUPAC Name Common Name Ball-and-Stick Model... 

TABLE 17.7 Some Esters in Fruits and Fiavorings Condensed Structural Formula and Name... 

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. 

Suppose we could look at butane, C4H10, as it rotates. Sometimes the —CH3 groups line up in front of each other, and at other times they are opposite each other. As the —CH3 groups turn around the single bond, the carbon chain in the condensed stmctural formulas may appear at different angles. For example, butane can be drawn using a variety of two-dimensional condensed structural formulas as shown in Table 11.3. All these condensed structural formulas represent the same compound with four carbon atoms. 

The molecular formulas of the alkanes are represented as C 2n+2 where n is the number of carbon atoms. The names, molecular formulas, and condensed structural formulas of the first ten alkanes are listed in Table 22-1 on page 700 of your textbook. 

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