Chapter 11: Introduction to Organic Chemistry: Hydrocarbons

Organic Chemistry

The study of carbon compounds.

Organic Compounds

Always contain carbon and hydrogen, and sometimes other nonmetals such as oxygen, sulfur, nitrogen, phosphorus, or a halogen.

Hydrocarbon

These organic compounds consist of only carbon and hydrogen.

saturated hydrocarbon

A hydrocarbon is referred to as a _____ when all the bonds in the molecule are single bonds.

Alkanes

These are a type of hydrocarbon in which the carbon atoms are connected only by single bonds

IUPAC system

A system for naming organic compounds devised by the International Union of Pure and Applied Chemistry.

subscript

It indicates the number of hydrogen atoms bonded to each carbon atom.

Molecular formula

It gives the total number of carbon and hydrogen atoms, but does not indicate their arrangement in the molecule.

Skeletal Formula

A simplified structure that shows the carbon skeleton in which carbon atoms are represented as the end of each line or as corners.

Conformations

The different arrangements that occur during the rotation of a single bond.

Cycloalkanes

Hydrocarbons can also form cyclic or ring structures, which have two fewer hydrogen atoms than the corresponding alkanes.

Cyclopropane

The simplest cycloalkane that has a ring of three carbon atoms bonded to six hydrogen atoms.

Substituent

When an alkane has four or more carbon atoms, the atoms can be arranged here, which is attached to the carbon chain.

Branched Alkane

An alkane with at least one branch.

Structural Isomers

When the two compounds have the same molecular formula but different arrangements of atoms.

Alkyl Group

An alkane that is missing one hydrogen atom.

Haloalkanes

Halogen atoms replace hydrogen atoms in an alkane.

methane, ethane, propane, and butane

These four alkanes are gases at room temperature and are widely used as heating fuels.

5-8

Alkanes having ____ carbon atoms are liquids at room temperature; they are highly volatile.

9-17

Liquid alkanes with _____ carbon atoms have higher boiling points and are found in kerosene, diesel, and jet fuels.

Motor oil

A mixture of high-molecular-weight liquid hydrocarbons and is used to lubricate the internal components of engines.

Mineral oil

A mixture of liquid hydrocarbons and is used as a laxative and a lubricant.

waxy solids

Alkanes with 18 or more carbon atoms are ____ at room temperature.

Paraffins

They are used in waxy coatings added to fruits and vegetables to retain moisture, inhibit mold, and enhance appearance.

nonpolar

Alkanes are ____, which makes them insoluble in water.

carbon–carbon

The _____ single bonds in alkanes are difficult to break, which makes them the least reactive family of organic compounds.

Alkenes and alkynes

_____ are families of hydrocarbons that contain double and triple bonds.

unsaturated hydrocarbons

Alkene and alkynes are _____ because they do not contain the maximum number of hydrogen atoms.

saturated hydrocarbons

Alkenes and alkyne react with hydrogen gas to increase the number of hydrogen atoms to become alkanes, which are _____.

Alkenes

These contain one or more carbon–carbon double bonds that form when adjacent carbon atoms share two pairs of valence electrons.

Alkyne

A triple bond forms when two carbon atoms share three pairs of valence electrons.

Cycloalkenes

These are some alkenes that have a double bond within a ring structure.

Cis–Trans Isomers

These are compounds that have different configurations because of the presence of a rigid structure in their molecule.

Cis Isomer

An isomer of an alkene in which similar groups in the double bond are on the same side.

Trans Isomer

An isomer of an alkene in which similar groups in the double bond are on opposite sides.

Hydrogenation

* H atoms add to each of the carbon atoms in a double bond of an alkene.
* The double bonds are converted to single bonds in alkanes.

Hydration

• An alkene reacts with water (H — OH).

• A hydrogen atom (H —) from water forms a bond with one carbon atom in the double bond, and the oxygen atom in —OH forms a bond with the other carbon.

Michael Faraday

In 1825, *_____* isolated a hydrocarbon called benzene, which had the molecular formula C6H6.

benzene

A molecule of _____ consists of a ring of six carbon atoms with one hydrogen atom attached to each carbon.

Aromatic Compounds

Family of benzene compounds.

August Kekulé

In 1865, *______* proposed that the carbon atoms in benzene were arranged in a flat ring with alternating single and double bonds between the carbon atoms.