Aim: What is an organic compound? Do Now: what are the key components to organic chemistry? Homework: Text Book Pg 632 – 648 Questions 1-5

Organic Chemistry Unit IX

I. Organic Compounds: defined Contains carbon which must have four bonds Have covalent bonds. Have low melting points. Have low boiling points. React slowly because of their complex bonding. May have symmetrical shapes (i.e.: tetrahedral) therefore are soluble in non-polar solvents. Form large molecules with triple, double and single bonds.

II. Nomenclature: Naming Organic Compounds Learn to use Table P

a) Types of Organic Compounds Hydrocarbons any compound that contains carbon and hydrogen 1. Alkanes – hydrocarbons that contains all single bonds among the carbons in any chain -Formula For Alkane CnH2n+2

Complete Structural Formulas Show the bonds between each of the atoms H H   H  C  H H C H CH4 , methane In methane, CH4 the four valence electrons of carbon are shared with the single electrons of four hydrogen (H) atoms. Each pair of electrons is a single bond, which can be drawn as a line. When a structure is drawn to show each bond, it is called a complete structural formula.

More Alkanes H H Condensed Structural Formulas H C C H CH3 CH3 H H Ethane H H H H C C C H CH3 CH2 CH3 H H H Propane The complete structural formula for ethane shows the single bonds between two carbon atoms and six H atoms. The complete structural formula of propane shows the 3-carbon chain with single bonds to the attached H atoms. To write a condensed structural formula, the H atoms are written as a group next to their respective C atoms.

Alkane Family Molecular Formula CH4 Name # carbons Structural Formula Methane 1 CH4 Molecular Formula CH4 The names of organic compounds are determined by the IUPAC rules (International Union of Pure and Applied Chemistry). The stem of the name states the number of carbon atoms in the carbon chain of the compounds. The suffix, in this case –ane, indicates the alkane family.

Alkane Family Continued Name # carbons Structural Formula Ethane 2 CH3CH3 Molecular Formula C2H6

Alkane Family Continued Name # carbons Structural Formula Propane 3 CH3CH2CH3 Molecular Formula C3H8

Other Alkanes Hexane 6 CH3CH2CH2CH2CH2CH3 Name # carbons Structural Formula Hexane 6 CH3CH2CH2CH2CH2CH3 Heptane 7 CH3CH2CH2CH2CH2CH2CH3 Octane 8 CH3CH2CH2CH2CH2CH2CH2CH3 Nonane 9 CH3CH2CH2CH2CH2CH2CH2CH2CH3 Decane 10 CH3CH2CH2CH2CH2CH2CH2CH2CH2CH3

Answer the following A. Draw butane? H H H H H C C C C H What is its molecular formula? C4H10

b) Alkenes – unsaturated hydrocarbons that contain one double bond among the carbons in any chain. Name Structure Molecular Formula C2H4 Ethene C3H6 Propene Butene C4H8

Answer the Following Why? H H H H H C= C-C-C- C H What is the molecular formula of pentene ? C5H10 Why? H H H H H C= C-C-C- C H H H H H

c) Alkynes- unsaturated hydrocarbons with one triple bond among the carbons in any chain Name Structure Molecular Formula Ethyne (acetylene C2H2 Propyne C3H4

Naming Alkenes and Alkynes When the carbon chain has 4 or more C atoms, number the chain to give the lowest number to the double or triple bond. 1 2 3 4 CH2=CHCH2CH3 1-butene CH3CH=CHCH3 2-butene CH3CCCH3 2-butyne

Using Table Q

Saturated and Unsaturated Compounds Saturated compounds (alkanes) have the maximum number of hydrogen atoms attached to each carbon atom Unsaturated compounds have fewer hydrogen atoms attached to the carbon chain than alkanes Unsaturated compounds contain double or triple bonds

Summary of Hydrocarbons Alkanes, Alkenes and Alkynes are members of a homologous series where each successive member has one more carbon and two more hydrogens If you arrange the series in alphabetical order which comes first , second and third ? Alkane – single bonds Alkene – double bond Alkyne – triple bond

Using the summary and the reference tables answer the following 1. Given CH4, C2H6,what is the next member ? C3H8 2. Which of the following has a double bond ? C4H10, C4H8 or C4H6 3. Which of the following is Pentyne ? C5H12 C3H4 C5H8 4. Which of the following is a saturated hydrocarbon ? 5. Draw 2-butene. C-C=C-C plus the Hs

Answer the following: What is the formula of Butene ? C4H8 What is the formula of Hexane C6H14 What is the formula of Butyne ? C4H6 Which of the following is an alkene ? C4H10 C4H6 or C4H8

d) Benzene Series 1. Characteristics: Aromatic hydrocarbon (ring structures) Contains alternating double bonds Displays chemical resonance Highly nonpolar due to the depolarization of shared electron (equally distributed). Formula: CnH2n-6 Examples: Benzene, Toluene, Napthalene

Benzene Toluene Napthalene