lecture 8.1 – organic chemistry and alkanes

Lecture 8.1 – Organic Chemistry and Alkanes

I. Organic Chemistry and Carbon

• Organic Chemistry is the branch of chemistry that studies carbon.

• • • Carbon can form long chains and rings by

bonding to itself

I. Hydrocarbons

• A molecule of only hydrogen and carbon is called a hydrocarbon.

• Hydrocarbons can be classified as alkanes, alkenes, or alkynes

• Alkanes are completely saturated hydrocarbons

II. Properties of Alkanes

• Alkanes release a large amount of energy when burned

• Alkanes are not soluble in water• The heavier an alkane is, the higher its boiling

point (only intermolecular force = London Dispersion Forces)

Lecture 8.2 – Alkenes and Alkynes

I. Alkenes

• Alkenes are unsaturated hydrocarbons that contain at least 1 double C – C bond.

II. Alkynes

• Alkenes are unsaturated hydrocarbons that contain at least 1 triple C – C bond.

III. Naming Alkenes and Alkynes

• When naming alkenes and alkynes, you need to state the location of the double/triple bond by stating the carbon it is located on

• E.g. 1 – propene, 2-octyne, etc.

Lecture 8.3 – Naming Hydrocarbons

I. Naming Hydrocarbons

1. Circle the LONGEST carbon chain2. Number all of the carbons in the longest

chain3. Circle all side chains4. Name the side chains by writing the carbon

number it is attached to and the name of the chain. NOTE – Add di, tri, etc. when you have the same side chain multiple times

II. Isomers• Isomers are compounds that have the same

molecular formula, but different structural formulas

• This different structure leads to different physical and chemical properties.

III. Practice

• Draw 3 isomers of pentane.

IV. Practice

• Draw 4 isomers of octane.

Lecture 8.4 –Functional Groups

I. Functional Groups

• Functional groups are specific groups of atoms or bonds that alter the physical and chemical properties of the hydrocarbon.

II. Halides (Halocarbon)

• Halocarbons are when a simple halogen from group 17 replaces a hydrogen atom in an alkane.

• Tend to be used as solvents and pesticides

III. Halocarbon Properties• Nonflammable and low reactivity• Boiling points are higher than alkanes because

of larger molecular weight and increased strength of London Dispersion Forces

• Haloalkanes are better solvents due to increased polarity

Lecture 8.6 – Types of Organic Reactions

I. Combustion Reactions

• When a hydrocarbon reacts with oxygen, carbon dioxide and water are produced.

• Ex.CH4 + O2 CO2 + H2O

II. Addition Reactions

• Addition reactions involve adding one or more atoms to an unsaturated hydrocarbon.

• A double covalent bond is converted into a single covalent bond and a triple covalent bond is converted into a double covalent bond.

III. Substitution Reactions• In a substitution reaction, one type of atom is

replaced with a different atom or group of atoms.

• Substitution reactions only happen to saturated hydrocarbons.

IV. Polymerization• A polymer is a large molecule composed of

many repeating units called monomers.

Lecture 8.7 – Types of Organic Reactions

I. Esterification • An esterification reaction is:

ORGANIC ACID + ALCOHOL ESTER + WATER• This process produces many common smells in

foods (especially fruits) and perfumes.

II. Saponification

• The general formula for a saponification reaction is:

• ESTER + INORGANIC BASE ALCOHOL + SOAP• REMEMBER THIS REACTION MAKES SOAP!

III. Fermentation

• In a fermentation reaction, the general reaction occurs:

Sugar Alcohol + Carbon Dioxide• Sugars have the empirical formula of CH2O