1. Organic Chemistry
Unit 4: Chapter 9

2. 9.1 Hydrocarbons Organic Compound – a covalent
compound containing carbon.
CH4, CH3CH2OH
Inorganic Compound – a compound that does not contain carbon.
NaCl, FeCl3
Hydrocarbon – compounds containing both carbon and hydrogen.
C3H8, C4H10

3. Natural Versus Synthetic
Many organic compounds exist naturally – sugars, starches, carbohydrates, fats, proteins, enzymes, DNA, wool, cotton, silk, etc.
Chemists can also synthesize (make) many organic compounds. As many as new organic compounds are made each year – cough medicines, painkillers, anti-depressants, perfumes, food flavorings, plastic, materials made of rubber or plastic, fabrics such as nylon, rayon, polyester, etc.
Most hydrocarbons come from the Earth.
Coal, Petroleum, and Natural gas are the main sources of fuel for humans.

4. 9.2 Representing Hydrocarbons
Organic chemistry is based on one element – CARBON.
Reasons :
C has four bonding locations
C can form single, double or triple bonds
These properties allow carbon to form a variety of structures, including chains and rings.

5. Representing Structures and Bonding
Complete Structural Diagram
Condensed Structural Diagram
shows all atoms in the molecule
shows bonds between carbons – not the hydrogens

6. Line Structural Diagram
Expanded Molecular Formula
shows no carbon or hydrogen atoms.
each point represents a carbon
shows grouping of atoms without drawing lines for bonds.
brackets are used to indicate the location of branched chains
CH3CH(CH3)CH2CH2CH3

7. 1 2 3 4 5 6 7 8 9 10 Basic Roots for Organic Compounds Meth Eth Prop
But 4
Pent 5
Hex 6
Hept 7
Oct 8
Non 9
Dec 10

8. 9.3 Classifying Hydrocarbons
Alkanes
hydrocarbons containing single covalent bonds
use suffix “ane”
known as aliphatic hydrocarbons – form chains and non-aromatic rings
formula CnH2n+2
C3H8, C4H10 , C6H14
Straight Chain Alkanes – Unbranched Alkanes
Naming:
use the number of carbons to get the root
add the suffix “ane”

9. Branched Hydrocarbons
Branched hydrocarbons have alkyl groups that come off of the main chain.
Prefixes are used to show how many alkyl groups there are;
di, tri, tetra, penta, etc.

10. IUPAC Rules for Alkane Nomenclature
1. Find and name the longest continuous carbon chain. 2. Identify and name groups attached to this chain. 3. Number the chain consecutively, starting at the end nearest a substituent group. 4. Designate the location of each substituent group by an appropriate number and name. 5. Assemble the name, listing groups in alphabetical order. The prefixes di, tri, tetra etc., used to designate several groups of the same kind, are not considered when alphabetizing. Always put a dash between all numbers and letters. Always put commas between numbers.

11. Isomers
organic compounds that have the same chemical formula but different structural arrangements.
Structural Isomers of C6H14
CH3-CH2-CH2-CH2-CH3
CH3-CH2-CH-CH2-CH3