Organic Chemistry= the study of carbon and most carbon compounds

Bonding of Carbon Atoms Carbon atoms have a tendency to covalently bond with other carbon atoms and form

chains.Straight chainsBranched chainsRing chains

Carbon atoms are able to form up to four covalent bonds:**Remember: Carbon has 4 valence electrons.

Carbon atoms can engage in single, double, or triple covalent bonds:

saturated compounds = contain only single bondsunsaturated compounds = contain at least 1 double or

triple bond

This double bond between the two carbon atoms makes this organic compound unsaturated.

Molecular Formulas – show the atoms and the number of atoms involved in a molecule but nothing else

Structural Formulas – show each type of atom and how they are arranged in a molecule

Molecular Formula Structural Formula Condensed Structural Formula

CH4 CH4

C2H6 CH3CH3

Molecular vs. Structural Formulas

Hydrocarbons= organic compounds that contain only atoms of hydrogen and carbon

Homologous series of hydrocarbons:

(a) Alkanes = contain only single covalant bonds

- General formula: CnH2n+2

(b) Alkenes = contain one double covalent bond

- General formula: CnH2n

(c) Alkynes = contain one triple covalent bond

- General formula: CnH2n-2

Naming Organic Compounds Naming straight-chained hydrocarbons:

Use Reference Table P (Organic Prefixes) and Table Q (Homologous Series of Hydrocarbons) to name & write the formulas.

When naming alkenes & alkynes, indicate where the double/triple bond is located in the molecule. **The carbons are numbered so as to keep the

number for the double bond as low as possible**The double bond is located on the 1st carbon…so its name would be: 1-butene

The double bond is located on the 2nd carbon…so its name would be: 2-butene

Both compounds have four carbons (use prefix but-) and a double bond (use ending –ene)

Both compounds have four carbons (use prefix but-) and a triple bond (use ending –yne)

The triple bond is located on the 1st carbon…so its name would be: 1-butyne

The triple bond is located on the 2nd carbon…so its name would be: 2-butyne

Naming Organic Compounds Naming branched hydrocarbons:

1) Find the longest carbon chain which contains the functional group or multiple bond if present and name it (using Tables P & Q to find correct prefix & ending).

2) Number the longest chain (left to right or right to left) so that the functional group/multiple bond/longest side chain (branch) is on the lowest numbered carbon possible.

3) Name each side group but change the ending to -yl.

4) Use a prefix di-, tri-, tetra-, etc. to denote how many side groups of each length are present.

5) Before naming the side group give the number of the carbon to which the side group is attached.

6) Arrange the side groups in alphabetical order ignoring the prefixes di-,tri-, etc.

Examples:1.) The longest chain has 5 carbons, so the prefix pent- must be used.

2.) There are only single bonds, so the ending –ane must be used.

4.) Since the side group is right in the middle, the carbons can be numbered from either side. The methyl group is located on the 3rd carbon.

3.) The side group has only one carbon, so use the prefix meth- and add the ending –yl: methyl.

Name: 3-methyl pentane

1.) The longest chain has 4 carbons, so the prefix but- must be used.

2.) There are only single bonds, so the ending –ane must be used.

4.) Count carbons so that the longest side chain has the lowest #. The first 2 methyl groups are located on carbon 2, and the next methyl group is located on carbon 3.

3.) Each side group has only one carbon, so use the prefix meth- and add the ending –yl: methyl. Since there are 3 methyl groups, use the prefix tri-: trimethyl.

Name: 2,2,3-trimethyl butane

Isomers= compounds with the same molecular formula, but different structural

arrangements

**As the # of carbon atoms in a compounds increases, the # of possible isomers also increases.**

Three of these compounds have the molecular formula C5H12. Which compound is not an isomer of the others?

Functional Groups= atoms or groups of atoms that can replace hydrogen atoms in a

hydrocarbon and give the compound distinctive physical and chemical properties

(1) Halides:= when any of the halogens

(F, Cl, Br, or I) replaces a hydrogen

atom in an alkane

- named by citing the location of the

halogen attached to the chain and

adding the appropriate prefix

(fluoro-, chloro-, bromo-, or

iodo-)Note: Table R provides examples on how to recognize and name compounds w/ each of the functional groups!

(2) Alcohols:= one or more hydrogen atoms of a hydrocarbon are

replaced by an –OH group (called a hydroxyl group)

- named by citing the location of the –OH

group and changing the ending to –ol.

- Classifying alcohols:

Note: The –OH group does not dissociate, and therefore alcohols are not bases/electrolytes. However, the –OH group does make alcohols polar molecules.

Monohydroxy alcohol:

one –OH groupDihydroxy alcohol:

two –OH groups

Trihydroxy alcohol:

three –OH groups

- Alcohols can also be classified according to the position of their –OH group:

PRIMARY (1o): the functional group is bonded to a carbon that is on the end of the chain.

SECONDARY (2o): The functional group is bonded to a carbon in the middle of the chain.

TERTIARY (3o): The functional group is bonded to a carbon that is itself directly bonded to three other carbons.

(3) Aldehydes:= the carbonyl group (-C=O) is found on the end carbon

- named by substituting –al in place of the final –e of the corresponding alkane name

(4) Ketones:= the carbonyl group (-C=O) is found on an interior carbon

atom that is attached to two other carbon atoms

- named by replacing the final –e from the corresponding alkane with –one; if necessary, cite which carbon atom the carbonyl

group is attached to.

(5) Ethers:= two carbon chains are joined together by an oxygen atom

bonded between two carbon atoms

- named by first naming the two methyl groups, followed by the word ether (when both R groups are the same, use

prefix di-)

(6) Organic Acids:= contain the carboxyl functional group (-COOH)

- named by replacing the –e in the corresponding alkane name with –oic acid

(7) Esters:= have the type formula R-CO-OR’ (R-CO-O- part of formula comes from an organic acid; the R’ part comes from

an alcohol- see Esterification)

- named for the alcohol and organic acid that make up the ester

(8) Amines:= formed when one or more of the hydrogen atoms of

ammonia are replaced by an alkyl group

- named by changing the alkane ending of –e to –amine and then numbering the alkane chain to show the location of the amine group

(9) Amides:= a compound formed by the combination of two amino acids

(See Condensation reaction)

- named by changing the carboxylic acid

acid reactant ending –oic acid with

-amide

Organic Reactions**Note: Generally occur more slowly than inorganic reactions. When covalently

bonded substances react, they must first break relatively strong existing bonds before making new bonds.**

(1) Combustion:

= Hydrocarbons burn in the presence of oxygen to produce water

and carbon dioxide

(2) Substitution:

= involves the replacement of one or more of the hydrogen atoms in a saturated hydrocarbon with another atom or group

(3) Addition:

= involve adding one or more atoms at a double or triple bond

Ethene

Ethene

(4) Esterification:

= the reaction between an organic acid and an alcohol to produce an ester plus water

(5) Saponification:

= when an ester reacts with an inorganic base to produce an alcohol and a soap

Organic Acid + Alcohol Ester + Water

(6) Fermentation:

= a chemical process in which yeast cells secrete the enzyme zymase and break down sugar into carbon dioxide and two carbon fragments of alcohol

(7) Polymerization:

= the formation of large polymer molecules

(a) Addition polymerization

= involves the joining of monomers of unsaturated compounds

(b) Condensation polymerization

= involves the joining of monomers by removing water from hydroxyl groups and joining the monomers by an ether or

ester linkage

Polymers = organic compounds make up of chains of smaller units covalently bonded to each other

Addition Polymerization:

Condensation Polymerization:

First 10 Alkanes in SeriesHydrocarbon Molecular Formula

Methane CH4

Ethane C2H6

Propane C3H8

Butane C4H10

Pentane C5H12

Hexane C6H14

Septane C7H16

Octane C8H18

Nonane C9H20

Decane C10H22

First 10 Alkenes in Series

Hydrocarbon Molecular Formula

Ethene C2H4

Propene C3H6

Butene C4H8

Pentene C5H10

Hexene C6H12

Septene C7H14

Octene C8H16

Nonene C9H18

Decene C10H20

Notice: There is no alkene corresponding to the methane of the alkane series. That is b/c there must be at least 2 carbon atoms to form a double bond.

First 10 Alkynes in Series

Hydrocarbon Molecular Formula

Ethyne C2H2

Propyne C3H4

Butyne C4H6

Pentyne C5H8

Hexyne C6H10

Septyne C7H12

Octyne C8H14

Nonyne C9H16

Decyne C10H18

Notice: There is no alkyne corresponding to the methane of the alkane series. That is b/c there must be at least 2 carbon atoms to form a triple bond.