(4.1-4.6) representing + naming of hydrocarbons

What is a hydrocarbon?

A compound made up of only hydrogen and carbon.

How are organic compounds represented using empirical formulae?

By showing the simplest possible ratio of atoms in a molecule.

How are organic compounds represented using molecular formulae?

By showing the actual number of atoms in a molecule.

How are organic compounds represented using general formulae?

By showing a ratio of atoms in a family of compounds in terms of ‘n’ where n is a varying whole number

(e.g. alkane molecules are C_n H_2n+2 )

How are organic compounds represented using displayed formulae?

By showing the spatial arrangement of

all the atoms and bonds in a molecule-

also known as the graphical formula.

How are organic compounds represented using structural formulae?

By showing enough information to make the structure clear.

• double and triple bonds shown

• identical group bracketed together

• side groups shows with brackets

What is an isomer?

Compounds that have the same molecular formula but different displayed formulae.

i.e same number of atoms but in a different arrangement

What is a homologous series?

A family of organic structures with similar structures and properties.

What are the characteristics of a homologous series?

• Same general formula

• similar chemical properties

• trends in physical properties

• same functional group

What is a functional group?

A group of atoms

bonded in a specific arrangement

that influences the properties

of the homologous series.

What does the prefix of an organic compounds name tell you?

no. of carbon atoms are in the longest continuous chain

Name the prefix if there is 1 carbon atom.

Meth-

Name the prefix if there are 2 carbon atoms.

Eth-

Name the prefix if there are 3 carbon atoms.

Prop-

Name the prefix if there are 4 carbon atoms.

But-

Name the prefix if there are 5 carbon atoms.

Pent-

Name the prefix if there are 6 carbon atoms.

Hex-

What can the reactions of organic compounds be classified into?

Substitution

Addition

Combustion

What is a substitution reaction?

When one functional group is replaced with another

What is an addition reaction?

When 2 or more molecules combine to form a larger molecule with no other products

What is a combustion reaction?

When an organic compound reacts with oxygen

forming carbon dioxide and water

(or CO if incomplete combustion)