Unit 17: Organic Chemistry Name given to the study of carbon and carbon compounds. Living things contain many organic compounds. Products of living things, such as petroleum, wood and coal supply the raw materials from which organic chemicals are obtained.

Characteristics of Organic Compounds A. Organic compounds are generally nonpolar in nature. (symmetrical charge distribution) B. Only a few are soluble in water. (These include ethanoic acid, various sugars and some alcohols)

C. Organic compounds are generally nonelectrolytes ; they do not ionize well and as a result are poor conductors of electricity. D. Due to weak intermolecular forces of attractions, organic compounds usually have low melting points.

E. Reaction rates of organic compounds tend to be slower than those of inorganic compounds. The bonding within the organic molecules itself (intramolecular as opposed to intermolecular forces) are covalent and very strongly held together.

Bonding A. Carbon has 4 valence electrons. Due to the hybridization of these valence sublevels, carbon has 4 sites for bonds, forming a tetrahedral structure.

B. Structural formulas are often used to represent the molecule: Ex: Methane CH 4

C. Isomers: compounds with the same molecular formula, but different structures, so different properties Ex: C 5 H 12

– Carbon can bond with a second carbon by sharing _ 1 _ pair(s) of electrons ( single bond) _ 2 _ pair(s) of electrons ( double bond) _ 3 _ pair(s) of electrons ( triple bond)

Hydrocarbons Organic compounds containing only H and C A. Homologous Series:a group of organic compounds with similar properties and related structures (each successive number increases by 1 C and 2 H)

Table Q Alkanes: C n H 2n+2 Alkynes: C n H 2n-2 Alkenes: C n H 2n Benzenes: C n H 2n-6 To name these compounds, you use prefixes dependent upon the number of carbons present in the substance. TABLE P

B. Aliphatic Compounds (Compounds that are aligned in a straight chain) 1. Alkanes: C n H 2n+2 All C to C bonds are single. This compound is said to be saturated -has the max # of H around each C possible

To name alkanes: Use the prefix + -ane # of cnamemolecular structural 1methaneCH 4 2ethane 3 4

Alkenes: C n H 2n Hydrocarbons containing one double carbon to carbon bond. Because of the double bond they are said to be unsaturated (they have less hydrogen atoms than do saturated compounds with the same number of carbons) *Cannot have a 1 carbon alkene*

To name alkenes: use prefix + -ene # Cnamemolecular structural 1*cannot have – you need 2 carbons for the double bond 2etheneC 2 H 4 3 4

– If the double bond is not on an end carbon, the name of the alkene will change as follows: Number the carbons from the end of each side…then use the smallest number to tell where the double bond is located.

3. Alkynes: C n H 2n-2 Unsaturated hydrocarbons with one triple carbon to carbon bond.

To name alkynes: use the prefix + -yne # Cnamemolecular structural 1*cannot have – you need 2 carbons for the triple bond 2ethyne 3 4

– If the triple bond is not on an end carbon, the name of the alkyne will change as follows: Number the carbons from the end of each side…then use the smallest number to tell where the triple bond is located.

Aromatic Hydrocarbons closed chain (ring chain) structures that are often unsaturated with alternating double and single bonds.

The Benzene Family: C n H 2n-6 *you should know the following two* – Benzene: C 6 H 6 – Toluene: C 7 H 8

Functional Groups an atom (ion) or group of atoms polyatomic ion) responsible for specific properties and characteristics of organic compounds Table R