3.1.1 - Nomenclature

What are organic compounds

Covalent compounds of the element carbon (C)

What are hydrocarbons

Compounds consisting of hydrogen and carbon ONLY

What is it meant by saturated

Contains Single C-C bonds only

What is it meant by unsaturated

Contains a C=C double bond

What is a homologous series

Compounds which have the same functional group

What are the characteristics of a homologous series

members of homologous series:

• have same General formula

• almost have same chemical properties due to same functional group

• Molecular formula differ by CH₂

• Show gradual change in physical properties (eg. Boiling Point)

What is a functional group

The reactive part of an organic molecule

What is the functional group for alkanes

What is the suffix of the functional group alkanes

-ane

Give an example of an alkane

Propane

What is the functional group for Alkenes

What is the suffix of the functional group alkene

-ene

If there is more than one double bond what is the suffix of the alkene

-diene (2)

-triene (3)

The stem of the carbon chain ends with an -a

eg. Penta-1,3-diene

How is an alkene named if an alcohol or Carboxylic acid functional group is present aswell

The suffix -en can go in front of the alcohol/Carboxylic acid suffixes

eg. but-2-enoic acid

Why does this happen

The alcohol and Carboxylic acid functional group have higher priority than the alkene group so take precedence (more importance) with numbering

Give an example of an alkene

But-2-ene

What is the functional group for alcohols

What is the suffix for alcohols

-ol

How would you name the molecule which has 2 -OH groups

Suffixes:

-diol

-triol

If there are more than one -OH add ‘e’ on stem name

eg: ethane-1,2-diol

How would you name the molecule with an alcohol along with another functional group

The priority group gets the suffix ending and the -OH named using prefix hydroxy-

eg: 2-hydroxypropanoic acid

Where does the priority groups stem from

Aldehydes

∴ Carboxylic acids are a priority group as aldehydes which are oxidised become Carboxylic acids

Give an example of an alcohol

Propa-1-ol

What is the functional group for aldehydes

What is the suffix for aldehydes

-al

How would you name the molecule if there is more than one aldehyde functional group

Suffix: -dial

Add ‘e’ to the stem

eg: pentanedial

What is an example of an aldehyde

Propanal

What is the functional group of a ketone

What is the suffix of a ketone

-one

How would you name the molecule if there is more than one aldehyde functional group

Suffix: -Dione

Add ‘e’ to the stem

eg: pentane-2,4-dione

Give an example of a ketone

Butanone

What is the functional group of carboxylic acid

What is the suffix of a Carboxylic acid

-oic acid

How would you name the molecule if there is more than one carboxylic acid functional group

Suffix: -dioic acid

Add ‘e’ to the stem

eg: Ethanedioic acid

What is an example of a Carboxylic acid

Ethanoic acid

What is the functional group of an ester

What is the suffix of an ester

-oate

What is an example of an ester

Methyl propanoate

What is the functional group of a Halogenoalkane

What are the prefixes of a Halogenoalkane

-fluoro

-chloro

-bromo

-iodo

How are Halogenoalkanes named with multiple functional groups

It’s listed in alphabetical order (ignores the di, tri)

eg. 5,5-dibromo-4-iodo-3-methylpent-1-ene

What is an example of a Halogenoalkane

2-bromopropane

What is the functional group for a nitrile

What is the suffix for a nitrile

-nitrile

Give an example of a nitrile

Propanenitrile

What are the 6 ways organic compounds can be represented by

• empirical formula

• Molecular formula

• General formula

• Structural formula

• Displayed formula

• Skeletal formula

What is a empirical formula

The simplest whole no. ratio of atoms of each elements in a compound

What is a molecular formula

The true numbers of atoms of each element in a compound

What is a General formula

the algebraic formula for homologous series

Give an example of a General formula

Eg. Alkenes = CₙH₂ₙ₊₂

What is a structural formula

Shows the structural arrangement of atoms within a molecule

What is the displayed formula

Shows every atom and every covalent bond in an organic compound

What is a skeletal formula

Shows only the bonds in the compound and any non carbon atom

With the assumption Hydrogen is bonded to the carbons unless stated otherwise

What is the shape around carbon atoms in saturated hydrocarbons

Tetrahedral

What is the bond angle around carbon atoms in saturated hydrocarbons

109.5°

What are the general rules for naming carbon chains

• use commas between numbers

• Use dashes between numbers and words

• Put numbers in ascending order

What is the general rule for naming functional groups

If the suffix of the functional group begins with a vowel remove the -e from the stem alkane name

eg: propane-1-ol x

propan-1-ol ✓

How do you name the molecule when there a 2+ of the same functional group

You name them:

• di- (2)

• tri- (3)

• tetra- (4)

• penta- (5)

• hexa- (6)

How do you name a molecule with 2 different functional groups

The functional groups are listed in alphabetical order regardless of where on the carbon chain it’s located

eg. 3-bromo-1-fluoropentane