1- Introduction to organic chemistry

The actual number of atoms of each element in a molecule

What is meant by the molecular formula?

C2H6

Ethane molecular formula

The simplest whole number ratio of atoms of each element in a compound

What is meant by the empirical formula?

CH3

Ethane empirical formula

Ethane skeletal

Each line is a carbon atom, starting from a bottom position

How does the skeletal formula represent molecules?

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Ethane displayed formula

CH3CH3

Ethane structural formula

In brackets, for example: CH3CH(CH3)CH3

How are branches represented in the structural formula?

How many carbons in the longest hydrocarbon chain/ring

1 - meth

2 - eth

3 - pro

4 - but

5 - pent

6 - hex

If the root ends in "ene" there will be a double bond present

What does the root of a systematic name tell us? Identify the 6 roots

Prefixes tell us the number of carbons in a side chain

1 - methyl

2 - ethyl

3- propyl

4- butyl

Hydrocarbon rings - cyclo

For example 2-METHYLbutane

Identify the prefixes of nomenclature

Alkane - ane

Alkene - ene

Halogenoalkane - none

Alcohols - ol

Aldehydes - al

Ketones - one

Carboxylic acids - oinc acid

Identify the suffixes of the functional groups

a) OH

b) C=OH

c) =O

d) C=O-OH

Identify the functional group for the following

a) Alcohols

b) Aldehydes

c) Ketones

d) Carboxylic acids

By a prefix

Chlorine - chloro

Bromine - bromo

Fluorine - fluoro

Iodine =- iodo

How are halogenoalkanes named?

You must number where the branch of carbons is.

In this instance the methyl group is on C2, hence

2-methyl

Displayed formula for 2-methylpentane

Even though iodine is on C1 and bromine is on C2, bromo comes before iodo as alphabetical order is prioritised over numerical

Displayed formula for 2-bromo-1-iodopropane

If you have more than one of the same functional group you can add either

2 - di

3 - tri

4 - tetra

In this instance both the 2 chlorine groups are on C1 hence the '1,1'

Displayed formula for 1,1-dichloroethane

If you have a double bond, you must number where the double bond is

In this instance, we label from right to left as we need the lowest number possible

Displayed formula for but-1-ene

Hex - longest hydrocarbon chain is 6C long even if it bends round

Methyl group on C4

Displayed formula for 4-methylhex-1-ene

Number from right to left as this gives the lowest numbers

Displayed formula for 2,3-dimethylbut-2-ene

Number from right to left as F comes before I in the alphabet. We want to give the functional group with the highest precedence the lowest number

Displayed formula for 1,2-difluoro-3,4-diiodobutane

.

Displayed formula for tetrachloromethane

.

Displayed formula for 1-bromo-2-chlorobutane

.

Displayed formula for propanone

Number from right to left as the OH functional group takes priority over methyl chain

Displayed formula for 3-methylbutan-2-ol

.

Displayed formula for 4-methylpentan-2-one

"al" ending as the functional group C=O is aldehyde

I

H

Displayed formula 2-methylbutanal

"one" ending as the functional group group is =O (ketone)

Number from right to left as function group takes priority

Displayed formula for 4-methylpentan-2-one

COOH carboxylic functional group gives "oic" acid suffix

Displayed formula for methanoicacid

Carboxylic acid group always on the end no need to number

Displayed formula for 2-chloropropanoicacid

Compounds with the same molecular formula but different structural formula

Define structural isomer

a) different arrangement of hydrocarbon chain (such as branching)

b) same functional groups attached to the main chain at different points

c) different functional groups

What is

a) Chain isomerism

b) Positional isomerism

c) Functional isomerism

2-bromo-propane

Both have molecular formula CH3CH7BR

Same function group Bromine but on different Carbons

Positional isomer of 1-bromo-propane

Same molecular formula but the double bond has been removed (functional group has changed)

Alkenes pair with cycloalkanes when producing functional group isomers

Functional group isomer of C4H8

Same molecular formula but they have different functional groups (aldehyde v ketone)

Aldehydes pair with ketones when forming functional group isomers

Functional group isomer of C3H6O

Same molecular formula but the O bonded to the H creates an alcohol group, whereas the other O is simply bonded to carbon atoms (ether)

Alcohols form pairs with ethers when producing functional group isomers

Function group isomer of C3H8O

Same molecular formula but functional group as changed from COOH (carboxylic acid) to COO (ester)

Carboxylic acids and esters form pairs when producing functional group isomers

Functional group isomer of C2H4O2

4

How many structural isomers does C4H9Br have?

5

There is no function group, it is just an alkane, this means it can only have different types of CHAIN isomers.

Make sure you don't just create a chain that bends round

How many structural isomers does C6H14 have?

.

Skeletal formula for 2,2-dimethylbutane

10

How many structural isomers for C5H10 have?

Give the IUPAC name of the chain isomer for but-1-ene

Methylpropene

Skeletal formula for 3-methylbutanal

Draw the displayed formula of C5H11Br that is the major product of the reaction of 2-methyl-but-2-ene with hydrogen bromide

What type of structural isomers can alkanes form

Chain only

How many structural isomers does C6H14 have

5

What is stereoisomerism?

Same structural formula but different arrangement of atoms in space

What is E and Z isomerism?

E = Priority group (highest atomic number) on diagonal side

Z = Priority group (highest atomic number) on same side

Compare either side of the double bond highest atomic number to find the priority group

But-2-ene E and Z isomerism

1,2-dibromo-1iodoethene E and Z isomerism

2,3-dihydroxylbut-2-ene E and Z isomerism

2-chloro-1-iodopropene E and Z isomerism

Draw the structure of (Z)-pent-3-en-2-ol