There are some general rules which you should remember when naming organic compounds:
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
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The longest unbranched chain containing the functional group is the parent molecule or simply the longest unbranched chain for alkanes. Remember that the longest chain can go round a bend.
Indicate the position of the functional group with a number, numbering from the end nearest the functional group.
Name the branches and indicate the number of branches.
Example:
Indicate the position of the branches with a number, numbering from the end nearest the functional group.
If there is more than one branch, the branches are identified in alphabetical order ignoring any di, tri etc.
Be aware!
Each branch needs to be numbered individually, even if they are attached to the same carbon atom.
The rule is a comma between numbers and a dash between numbers and letters.
Alkanes
The alkanes don't contain a functional group and so the branches are numbered from the end that gives the lowest set of position numbers for the branches.

Use the above rules to see how the names of the alkanes below are built up.
Alkenes and alkynes
The functional group in the alkenes is the carbon to carbon double bond.
The functional group in the alkynes is the carbon to carbon triple bond.
The basic rules of naming apply.
The position of the double or triple bond is indicated by a number before the -ene or -yne part of the name.
Example:

Alcohols
The functional group in the alcohols is the hydroxyl group (-OH).
Alcohols end in the letters -ol
The basic rules of naming apply.
The position of the hydroxyl functional group is indicated by a number before the -ol part of the name.
Be aware!
Alcohols can also be termed primary, secondary or tertiary.
Primary has the -OH on the end of a chain.
Secondary has the -OH on a non-branched carbon atom along the chain.
Tertiary has the -OH on a branched carbon atom along the chain.
Example:
Aldehydes
All aldehydes contain a carbonyl functional group. The carbonyl group will never have a position number in an aldehyde as it is always on the end of the carbon chain.
Aldehydes end in the letters -al .
The basic rules of naming apply.
Examples:

Ketones
Ketones also contain a carbonyl functional group but in ketones it is never on the end of a carbon chain.
Ketones end in the letters -one .
The naming rules in part 1 apply as before.
Example:
Carboxylic acids
Carboxylic acids contain the carboxyl functional group (-COOH) The carboxyl group will never have a position number in a carboxylic acid as it is always on the end of the carbon chain.
Carboxylic acids end in -oic acid.
The basic rules of naming apply.
Examples:

Esters
An ester is made from an alcohol and a carboxylic acid.
Esters have their own rules for naming.
The first part of the name comes from the alcohol and it ends with the letters -yl .
The second part of the name comes from the carboxylic acid and it ends with the letters -oate .
Examples:
Name of Alcohol Name of Carboxylic acid Name of ester ethanol propanoic acid ethyl propanoate butanol methanoic acid butyl methanoate pentanol ethanoic acid pentyl ethanoate
It is also possible to form names from structures.
The ester is divided between the carbon and oxygen in the ester functional group.
The acid part contains the carbonyl group.

Examples:
Addition reactions only occur with unsaturated compounds, that is, compounds containing a carbon to carbon double bond or a carbon to carbon triple bond. In other words, alkenes or alkynes.
Addition to alkenes
The most common addition reactions involve addition of a small molecule like a halogen (1) , hydrogen (2) , a hydrogen halide (3) or water (4) . Examples of these reactions are shown below:

The small molecule always adds across the double bond . For example, in this case of reaction (1) above the double bond is between carbon atoms 1 and 2, so the bromine atoms will be in position 1, 2.
All of the products are now saturated as they contain only single carbon to carbon bonds.
The addition of hydrogen, reaction (2) , is also known as hydrogenation .
The addition of a hydrogen halide, reaction (3) , to an alkene might produce a mixture of isomers depending on how the hydrogen halide

adds across the carbon to carbon double bond.
The addition of water, reaction (4) , is a very important reaction to remember because it produces alcohols. Addition of water is also known as hydration .
Addition to alkynes
Addition to an alkyne is a two stage process: with the possibility of isomers being produced.
Complete addition to an alkyne will require twice the quantity of halogen (1) , hydrogen (2) or hydrogen halide (3) . Examples of these reactions are shown below:
Dehydration
Hydration involves the addition of water to an unsaturated molecule.
Dehydration is the reverse of hydration and involves the removal of

water from a molecule.
The dehydration of an alcohol is an important way to make alkenes.
Be aware!
Don't confuse hydration and dehydration with condensation and hydrolysis (see Making and breaking esters).
The most important oxidation reactions are oxidation of alcohols
(alkanols) and aldehydes (alkanals) using a variety of oxidising agents.
Oxidation just means joining with oxygen.
Complete combustion is an extreme oxidation reaction.
Example: Complete combustion of methanol.
2 CH
3
OH + 3 O
2
2 CO
2
+ 4 H
2
O
Alcohols burn in oxygen to produce carbon dioxide and water.
In organic chemistry, oxidation can mean both adding oxygen or removing hydrogen.
The oxidations to remember are:
Example: oxidation of ethanol (primary alcohol).

Example: oxidation of propan-2-ol (secondary alcohol).
Both examples show that oxidation leads to an increase in the oxygen to hydrogen ratio.
Tertiary alcohols are not easily oxidised because, unlike primary and secondary alcohols, they do not have a hydrogen attached to the same carbon atom as the hydroxyl group.
Of course, the opposite of oxidation is reduction and the previous two examples can also go in reverse:
Example: reduction of ethanoic acid

This example shows how the oxygen to hydrogen ratio decreases during reduction.
The oxidising agents
It is important to remember the colour changes which occur in the reactions, both starting and final colours.
Oxidising reagents must always be reduced and the ion-electron equations for the reactions are on page 11 of the Higher data booklet.
Summary of oxidising agents:
Oxidising agent
Change in appearance black solid
Reason brown solid Cu
2+
+ 2e
-
Copper(II) oxide
Acidified potassium dichromate solution orange solution green solution
(blue)Cr
2
O to Cr
7
3+
2+
Cu
(aq) reduced
(aq)
Benedict's or
Fehling's solution
Tollen's
Reagent blue solution red precipitate colourless solution silver mirror orangeCu
2+
+ e
-
Ag
+
(aq) + e
Ag(s)
-
Cu
+
Prescribed practical activity
Oxidising agents can be used to distinguish between aldehydes and ketones. Because aldehydes can be oxidised, they will produce the colour changes in oxidising agents shown above. Ketones can't be easily oxidised and so do not produce these colour changes.
An ester is made from a carboxylic acid and an alcohol.

This is a condensation reaction, where two molecules join together to form one larger molecule (the ester) and a small molecule, usually water.
Example: formation of ethyl propanoate.
The ester link is formed by the reaction of a hydroxyl group with a carboxyl group.
The reaction of an alcohol with a carboxylic acid is, in fact, a reversible reaction. In the reaction, some of the ester molecules formed are split up again into the alcohol and carboxylic acid they are made from. This happens when water reacts with the ester link. This is a hydrolysis reaction.
A hydrolysis reaction is one where a large molecule is split into two smaller molecules by reaction with water.
When an alcohol reacts with a carboxylic acid an equilibrium is produced. The equation for the reaction contains a double arrow. The forward reaction is a condensation reaction and the reverse reaction is a hydrolysis reaction.
Example: formation of methyl ethanoate.