# 14: Organic Chemistry - Alkanes and Halogenated Hydrocarbons


We begin our study of organic chemistry with the alkanes, compounds containing only two elements, carbon and hydrogen, and having only single bonds. There are several other kinds of hydrocarbons, distinguished by the types of bonding between carbon atoms and by the properties that result from that bonding. We will first examine hydrocarbons with double bonds, with triple bonds, and with a special kind of bonding called aromaticity. Then we will study some compounds considered to be derived from hydrocarbons by replacing one or more hydrogen atoms with an oxygen-containing group. Finally, we focuse on organic acids and bases, after which we will be ready to look at the chemistry of life itself—biochemistry—in the remaining five chapters.

• 14.1: Organic Chemistry
Today organic chemistry is the study of the chemistry of the carbon compounds, and inorganic chemistry is the study of the chemistry of all other elements. Organic chemistry is the study of carbon compounds, nearly all of which also contain hydrogen atoms.
• 14.2: Structures and Names of Alkanes
Simple alkanes exist as a homologous series, in which adjacent members differ by a $$CH_2$$ unit.
• 14.3: Alkenes- Structures and Names
Alkenes are hydrocarbons with a carbon-to-carbon double bond.
• 14.4: Alkynes
Alkynes are similar to alkenes in both physical and chemical properties. For example, alkynes undergo many of the typical addition reactions of alkenes. The International Union of Pure and Applied Chemistry (IUPAC) names for alkynes parallel those of alkenes, except that the family ending is -yne rather than -ene. The IUPAC name for acetylene is ethyne. The names of other alkynes are illustrated in the following exercises.
• 14.5: Branched-Chain Alkanes
Alkanes with four or more carbon atoms can exist in isomeric forms.
• 14.6: Condensed Structural and Line-Angle Formulas
Condensed chemical formulas show the hydrogen atoms (or other atoms or groups) right next to the carbon atoms to which they are attached. Line-angle formulas imply a carbon atom at the corners and ends of lines. Each carbon atom is understood to be attached to enough hydrogen atoms to give each carbon atom four bonds.
• 14.7: IUPAC Nomenclature
Alkanes have both common names and systematic names, specified by IUPAC.
• 14.8: Physical Properties of Alkanes
Alkanes are nonpolar compounds that are low boiling and insoluble in water.
• 14.9: Physical Properties of Alkenes
The physical properties of alkenes are much like those of the alkanes: their boiling points increase with increasing molar mass, and they are insoluble in water.
• 14.10: Chemical Properties of Alkanes
The alkanes and cycloalkanes, with the exception of cyclopropane, are probably the least chemically reactive class of organic compounds. Alkanes contain strong carbon-carbon single bonds and strong carbon-hydrogen bonds. The carbon-hydrogen bonds are only very slightly polar. Alkanes can be burned, alkanes can react with some of the halogens, breaking carbon-hydrogen bonds, and alkanes can crack by breaking the carbon-carbon bonds.
• 14.11: Chemical Properties of Alkenes
Alkenes undergo addition reactions, adding such substances as hydrogen, bromine, and water across the carbon-to-carbon double bond.
• 14.12: Halogenated Hydrocarbons
The replacement of an hydrogen atom on an alkane by a halogen atom—F, Cl, Br, or I—forms a halogenated compound.
• 14.13: Cycloalkanes
Many organic compounds have cyclic structures.
• 14.14: Organic Chemistry - Alkanes and Halogenated Hydrocarbons
Hydrocarbons are the simplest organic compounds, but they have interesting physiological effects. These effects depend on the size of the hydrocarbon molecules and where on or in the body they are applied. Alkanes of low molar mass—those with from 1 to approximately 10 or so carbon atoms—are gases or light liquids that act as anesthetics.
• 14.15: Organic Reactions
Organic reactions require the breaking of strong covalent bonds, which takes a considerable input of energy. In order for relatively stable organic molecules to react at a reasonable rate, they often must be modified with the use of highly reactive materials or in the presence of a catalyst. In this lesson, you will learn about several general categories of organic reactions.
• 14.E: Organic Chemistry- Alkanes and Halogenated Hydrocarbons (Exercises)
Select problems and solutions to chapter.
• 14.S: Organic Chemistry- Alkanes and Halogenated Hydrocarbons (Summary)
Summary of Chapter.
• 14.S: Unsaturated and Aromatic Hydrocarbons (Summary)
A brief summary of the chapter.

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