Pent- prefix

The higher members, beginning with pentane, are named systematically with a numerical prefix (pent-, hex-, hept-, etc., to denote the number of carbon atoms) and with the ending -ane to classify the compound as a paraffin hydrocarbon, as in Table 3-1. To specify a continuous-chain hydrocarbon, the prefix n- (for normal) sometimes is used. However, in the absence of any qualifying prefix, the hydrocarbon is considered to be normal or unbranched and we shall not use this prefix henceforth. You should memorize the names up to C10H22. 

You may be surprised to hear that practising organic chemists use systematic names at all in view of what we have just described, but they do Systematic names really begin with derivatives of pentane (C5H12) since the prefix pent- means five, whereas but- does not mean four. Chemists refer to simple derivatives of open chain and cyclic compounds with 5 to about 20 carbon atoms by their systematic names, providing that there is no common name in use. Here are some examples. 

Put the complete compound name together in this general form prefix + root + suffix. The name of the compound is 2-methyl + pent + ane = 2-methylpentane. 

There are a number of prefixes that show the number of particular atoms or radicals contained in a compound. Some of the most common are di and bi, meaning 2 tri, meaning 3 tetra, meaning 4 and pent, meaning 5. Thus, ammonium dichromate indicates the presence of 2 chromate radicals and sodium tetraborate the presence of 4 borate radicals. 

Names.—The names of the different hydrocarbons are similar and are in harmony with the idea of an homologous series. The common termination ane is given to all and, above the fourth member, a Greek numerical prefix indicates the number of carbon atoms in the molecule. The five-carbon compound is pent-ane, the six carbon hex-ane, etc. The first four members have special non-numerical prefixes as methane, eth-ane, prop-ane and but-ane. Similarly the radicals of each hydrocarbon simply take the termination yl in place of ane, thus, but-yl, pent-yl, hex-yl, etc. 

The presence of two or more of the same substituent is indicated by the prefixes di- (two), tri- (three), tetra- (four), pente- (five), and so forth. The prefixes are ignored in determining the alphabetical order of the substituents ... 

The name pentane derives from the Greek pente, meaning five, indicating that the molecule has five carbon atoms. The other names still use the term pentane, with a prefix iso or neo, trying to convey the fact that these are isomeric molecules. Naming the isomers can become cumbersome when the number of isomers increases. For this reason, chemists have created a standard naming system. ... 

Monosaccharides have the general formula C H2 0 , with one of the carbons being the carbonyl group of either an aldehyde or a ketone. The most common monosaccharides have from three to nine carbon atoms. The suffix indicates that a molecule is a carbohydrate, and the prefixes trir, tetr-, pent-, and so forth, indicate the number of carbon atoms in the chain. Monosaccharides containing an aldehyde group are classified as aldoses those containing a ketone group are classified as ketoses. 

The prefixes tri-, tetr-, pent-, and so on show the number of carbon atoms in the chain. 

The International Union of Pure and Applied Chemistry (lUPAC) method of naming alkanes is fairly simple. The names of all alkanes end in one. The prefixes, based on the number of carbons in the molecule, make naming a lot like counting. Meth- (1 carbon), eth- (2), prop- (3), but- (4), pent- (5), hex-(6), hep- (7), oct- (8), non- (9), and dec- (10) are the basic prefixes. If you know these, you will be able to breeze through naming. 

Latin word for a given number, but there are exceptions. A one-carbon unit has the prefix meth, two carbons are eth, three carbons are prop, four carbons are but, and five, six, seven, eight, nine, and ten carbons are derived from the Latin terms pent, hex, hept, oct, non, and dec, respectively. 

Indicate the prefix that is used for the molecule (CH3)2CH(CH2)2CH20H meth, eth, prop, but, pent, or hex. 

The alkanes are a class of hydrocarbons in which the atoms are connected by single bonds. One of the most common uses of alkanes is as fuels. Methane, used in gas heaters and gas cooktops, is an alkane with one carbon atom. The alkanes ethane, propane, and butane contain two, three, and four carbon atoms, respectively, connected in a row or a continuous chain. As we can see, all the names for alkanes end in ane. Such names are part of the lUPAC (International Union of Pure and Applied Chemistry) system used by chemists to name organic compounds. Alkanes with five or more carbon atoms in a chain are named using the prefixes pent (5), hex (6), kept (7), oct (8), non (9), and dec (10) (see Table 6.14). 

Monosaccharides can be further classified by their most highly oxidized functional group. Monosaccharides are called aldoses if their most highly oxidized functional group is an aldehyde and ketoses if their most highly oxidized functional group is a ketone. The suffix -ose indicates that a compound is a carbohydrate. The prefix aldo- or keto- indicates that the compound is an aldehyde or ketone. The prefixes tri-, tetr-, pent-, and hex- indicate the number of carbon atoms in an aldose or ketose. Aldoses are numbered from the carbonyl carbon atom ketoses are numbered from the end of the carbon chain closest to the carbonyl carbon atom. 

Alkanes with five or more carbon atoms in a chain are named using the prefixes pent (5), hex (6), hept (7), oct (8), non (9), and... 

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