Learn about the physical properties of organic compounds. Discover some examples of melting/boiling points, solubility, odor, and density of organic compounds. An isomer of organic molecules are those that have the same technical chemical formula, but are arranged differently.

Other groups which are attached to the parent chain are called substituents. The IUPAC nomenclature of organic chemistry is the standardized official naming rule of organic compounds, developed by the IUPAC. In this page we will discuss the IUPAC naming of alkanes, branched-chain alkanes, alkanes what is the potential difference δvab? with substituents, and cycloalkanes. Branched alkanes have side chains, so the name of a branched alkane specifies the longest continuous chain and the identity and position of the side chains . The position of the alkyl group is indicated by the number of the carbon atom to which it is attached.

All four structures have a double bond and thus meet rule 1 for cis-trans isomerism. Alkenes are hydrocarbons with a carbon-to-carbon double bond. An alkene has a double bond; an alkane has single bonds only. Just as there are cycloalkanes, there are cycloalkenes. These compounds are named like alkenes, but with the prefix cyclo- attached to the beginning of the parent alkene name. Note that the numbering of the parent chain is always done in such a way as to give the double bond the lowest number, even if that causes a substituent to have a higher number.

The fourth carbon of C4H8 can be placed in any of the labeled positions to produce a total of four different molecules . Isomers are different molecules with the same formula. Draw line-wedge-dash, Lewis, condensed, and skeletal structures of alkanes.

Arrange these carbocations in order of increasing stability. Triphenylcarbocation is tertiary carbocation and the positive charge is on the carbon atom which is stabilized by the three phenyl group by resonance. Due to the resonance the stability increases. The structure of triphenylmethylcation is given below. This is very stable and some of its salts can be stored for months. Explain the cause of the high stability of this cation.

If you count the carbons and hydrogens, you will see that they no longer fit the general formula CnH2n+2. By joining the carbon atoms in a ring, you have had to lose two hydrogen atoms. Cycloalkanes again only contain carbon-hydrogen bonds and carbon-carbon single bonds, but this time the carbon atoms are joined up in a ring. Some common addition polymers are listed in Table 1.8 “Some Addition Polymers”. Note that all the monomers have carbon-to-carbon double bonds.

Thus, the proper nomenclature of this alkane is 4-ethyloctane. Note that a dash is used to separate the number from the substituent. The nomenclature becomes more complex if the alkane branches.