Intro Organic Chemistry (need to add isomerism)

Empirical formula

The simplest ratio of atoms of each element in a compound.

Molecular formula

The formula showing the actual ratio of atoms of each element in a compound.

Structural formula

Gives the number and type of atoms in a molecule and shows how they are bonded together

Skeletal Formula

A straight line represents a carbon - carbon bond.

Homologous Series

• They show a gradual change in physical properties.

• They have similar chemical properties.

Alkene - General Formula

Halogenoalkane General Formula

Alcohol General Formula

Aldehyde General Formula

Ketone General Formula

Carboxylic Acid General Formula

Ester General Formula

Amine General Formula

Nitrile General Formula

Structural Formula - Alkene

Structural Formula - Halogenoalkane

Structural Formula - Alcohol

Structural Formula - Aldehyde

Structural Formula - Ketone

Structural Formula - Carboxylic acid

Structural Formula - Ester

Structural Formula - Amine

Structural Formula - Nitrile

Nomenclature - What does the stem of the name come from?

The longest carbon chain

Nomenclature - How are the side chains and functional groups’ position decided?

Numbering the carbon atoms from the side that gives the lowest possible numbers in the name

How are side chains shown in structural formulas?

Through brackets: ()

How do you indicate more than one of the same alkyl side-chain or functional groups in a compound?

In front of its name is added: di- (for two), tri- (for three) or tetra-(for four)

How are multiple alkyl side-chains ordered?

In alphabetical order

How are adjacent numbers separated?

By a comma: ,

How are numbers and words separated?

By a hyphen: -

What are the two types of isomerism?

• structural

• Stereo

Structural isomerism

• This occurs when substances have the same molecular formula but different structural formula

What we the different types of structural isomers?

• chain

• Position

• Functional group

Chain isomers

They belong to the same homologous series but have a different carbon chain (e.g branched).

What are the similarities in chain isomers?

Chemical properties

What are the differences on chain isomers?

Boiling point

Why do branched chain isomers have lower boiling points?

• branched chain molecules cannot pack as closely together and have weaker VdW between their molecules which take less energy to break.

Position isomers

• they have their functional groups in different positions

• DO NOT WRITE AS ‘POSITIONAL’

Functional group isomers

• They have the same molecular formula but different functional groups and so belong to different homologous series.

What is sterioisomerism?

This occurs when substances have the same molecular and structural formula but have a different spatial arrangement of their atoms.

What is a example of sterioisomerism?

E/Z isomerism

What is E/Z isomerism?

When a carbon - carbon double bond prevents rotation and each carbon on the double bond has two different groups attached to it.

When does the Z form of E/Z isomerism occur?

When two atoms of each pair of higher atomic number, therefore higher priority group, are on the same side of the C=C double bond.

When does the E form of E/Z isomerism occur?

When two atoms of each pair of higher atomic number, therefore higher priority group, are on different sides of the C=C double bond.