ORGANIC CHEMISTRY  Organic chemistry is the study of containing compounds derived from living organisms.  Oil is formed over millions of years from the break down of dead and million compounds- natural & synthetic.  Crude Oil (petroleum) is a mixture of many thousands of these different compounds and is the main source of many of these chemicals.  They are called because they predominantly contain the elements hydrogen and carbon.

Distillation of Crude Oil Lower boiling point substances and move up. As the temp drops substances and run off temp temp

Homologous series This is a series of compounds which all contain the same group, and have similar chemical properties. ALKANESALKENESALCOHOLS CH 4 CH 2 =CH 2 CH 3 OH CH 3 -CH 3 CH 2 =CH – CH 3 CH 3 CH 2 OH Each has a formula: : C n H 2n+2 The members of the series differ by the number of units. CH 3 -CH 3, CH 3 -CH 2 -CH 3, CH 3 -CH 2 -CH 2 -CH 3 Graduation in physical properties: eg: boiling points. CH 4 (......), C 8 H 18 ( ), C 30 H 62 ( )

ALKANES SATURATED HYDROCARBONS – contain maximum amount of ……………………………. - only ……………………….. bonds (no ……………………….. bonds) NAMING ALKANES No of C atomsPrefixFormulaAlkane 1MethCH 4 Methane 2EthCH 3 Ethane 3PropCH 3 CH 2 CH 3 Propane 4ButCH 3 CH 2 CH 2 CH 3 Butane 5PentCH 3 CH 2 CH 2 CH 2 CH 3 Pentane 6HexC 6 H 14 Hexane 7HeptC 7 H 16 Heptane 8OctC 8 H 18 octane

Functional groups The functional groups are ………………. or ………………….. of atoms which determine the ……………………. of organic molecules.

STRUCTURES OF ALKANES METHANE ………. Bond Angle …………….Shape……………………… Can be illustrated as:

ETHANE. Molecular formula …………... Structural formula:……………………….. OR ……………………………….

ETHANE. Molecular formula C 2 H 6 Structural formula: CH 3 CH 3 or H H H C C H H H Atoms are able to spin around a single bond there is free rotation.

PROPANE. Both ethane and propane are “……………………” chain molecules BUT!! Bonds are ……… 90 o molecules are NOT…………….!!! Schematic formula formula: C 3 H formula: CH 3 CH 2 CH 3 or H H H H C C C H H H H

PROPANE. Molecular formula: C 3 H 8 Structural formula: CH 3 CH 2 CH 3 or H H H H C C C H H H H Both ethane and propane are “straight” chain molecules BUT!! Bonds are NOT 90 o molecules are NOT STRAIGHT!!! Straight = no branches! Schematic formula Ethane and propane are also colourless and odourless flammable gasses. They have slightly higher boiling points due to their greater molecular weights.

ISOMERS C 4 H 10 - can have two different structures Straight chain. CH 3 CH 2 CH 2 CH 3 BUTANE Branched chain CH 3 CH CH 3 CH 3 METHYL PROPANE Compounds that have the same molecular formula but different structural formula are said to be ISOMERS of each other. TASK: illustrate the structures of the three different isomers of C 5 H 12. Use models OR CHEMSKETCH to help you. branch

Names & Structures Examples 2- methylbutane 2,2 – dimethyl propane TASK: illustrate the structures of: 2-methylpentane. 2,3 – dimethylbutane. 2,2,3 -trimethylpentane The 2 can be left off as there are ……………………………………………… 2 and 3-methylbutane are the same molecule!

THE RULES FOR NAMING ORGANIC COMPOUNDS 1.Choose the longest unbroken chain of Carbon atoms and assign a name for the carbon chain using the prefixes; meth-1,eth-2 etc. 2.Identify any carbon chain branches (alkyl groups). These are assigned names using the same prefixes as above along with the suffix “-yl” – methyl, ethyl etc. 3.Identify the functional groups present in the molecule. Assign a prefix or suffix according to their homologous series. These will be written in front of the name of the carbon chain. 5.Number the Carbon atoms in the longest chain so that the branches/functional groups have the lowest number possible. Allocate a number for every group/branch no matter how many times it occurs. Where groups are on the same carbon write their names in alphabetical order. 6.Prefixes are used for groups that occur more than once. Di – 2Tri – 3Tetra – 4Penta – 5 etc. 7.Groups are written in alphabetical order. 8.The final name is written as one word with commas between numbers, hyphens separating numbers from words.

Give the names of the following alkanes (a)CH 3 CH 2 CH CH 2 CH 3 CH 3 (b) CH 3 CH CH 2 CH CH 3 CH 3 CH 3 (c) CH 3 C(CH 3 ) 2 CH 2 CH(CH 3 ) CH 2 CH 3 (d) CH 3 CH 2 CH(CH 3 )C(CH 3 ) 3

The shape around the double bond is … The bond angle around the double bond is C C  bond   ……………….. ……….. Represented as C C Structure of Alkenes

Examples of Alkenes ………………, C 2 H 4 H C C H OR ……………………. PROPENE CH 2 CH CH 3 TASK: Use ball & stick models or sketches to construct and name 3 different structures for C 4 H 8 each one with one double bond.

Alkynes H-C ≡ C-H H-C ≡ C-CH 3 H-C≡C-CH 2 -CH 3 CH3-C≡C-CH3 …….yne ……..yne …………-1-yne ………….yne Very reactive Triple bond unstable! Attracts electrophiles. x Alkynes are very unstable and reactive. Acetylene burns with very high temp? C x x x