Summary A Level Edexcel Chemistry - Topic 6 - Organic Chemistry 1/I

💡
Topic 6 - Organic Chemistry 1
The Basics
What is a homologous series?

A homologous series is a bunch of organic compounds that have the same
functional group and general formula

Consecutive members of a homologous series differ by -CH2

Name all the homologous series with their prefix/suffix and an example

Alkanes -ane e.g. propane CH3CH2CH3

Branches alkanes -alkyl (-yl) e.g. methylpropane
CH3CH(CH3)CH3

Alkenes -ene e.g. propene CH3CH=CH2

Halogenoalkanes chloro-/bromo-/iodo- e.g. chloroethane CH3CH2Cl

Alcohols -ol e.g. ethanol CH3CHO

Aldehydes -al e.g. ethanal CH3CHO

Ketones -one e.g. propanone CH3COCH3

Cycloalkanes cyclo-....-ane e.g. cyclohexane C6H12

Carboxylic Acids -oic acid e.g. ethanioc acid CH3COOH




Organic Reactions
Name the 7 main reactions types and describe them

Addition

joining two or more molecules to form a larger molecule



Topic 6 - Organic Chemistry 1 1

, Polymerisation

joining together lots of simple molecules to form a giant molecule

Elimination

when a small group of atoms break away from a larger molecule

Subsitution

when one species is replaced by another

Hydrolysis

splitting a molecule into 2 new molecules by addin H+ and OH- drived from
water

Oxidation

any reaction in which a species loses electrons

Reduction

any reaction in which a species gains electrons

What is a mechanism?

A mechanism breaks down a reaction into indivisual stages

Draw a reaction and mechanism to show how chloromethane reacts with
aqueous potassium hydroxide to form methanol and potassium chloride




Topic 6 - Organic Chemistry 1 2

, Isomerism
What is meant by an Isomer?

Two molecules are isomers of each other if they have the same molecular
formula but the atoms are arranged differently

Describe chain isomers

The carbon skeleton can be arranged in different ways, branched or straight

These isomers have similar chemical properties BUT physical properties such
as BP will be different due to the change in shape

Describe positional isomers

here the skeleton and functional group can be the same, only with the
functional group attached to a different carbon

these have different physical properties and chemical properties might be
different too

Describe functional group isomers

the same atoms can be arranged into different functional groups

These have very different physical and chemical properties


Alkanes
What is an alkane? General formula?

Alkanes are saturated hydrocarbons because all the carbon carbon bonds are
single and they've got carbon and hydrogen atoms only

C n H 2n+2

Why are alkanes unreactive?

alkanes are uncreative because they are non polar with low electron density
between the carbon atoms

Describe hetrolytic fission



Topic 6 - Organic Chemistry 1 3

, In hetrolytic fission the bond breaks unevely with one of the bonded atoms
recieving both electrons from the bonded pair. Two different substances can be
formed - e.g. a positively charged cation and a negatively charged anion.




Describe homolytic fission

In homolytic fission the bond breaks evenly and each bonding atoms
receives one electron from the bonding pair. Two electrically unchagred
radicals are formed. Radicals are particels that have an unpaired electron.
Radicals are very reactive because of this.




How does an Alkane react with a Halogen?

presence of UV light

Radical subsitution reaction

forming halogenoalkanes

Describe the initiation stage

during initiation radicals are produced




Topic 6 - Organic Chemistry 1 4