Alcohols

Common uses of alcohols

• petrol

• cosmetics

• perfumes

• manufacturing

• plastics

• antiseptics

• household cleaners

• beer & wine

Alcohols are a homologous series of ___

hydrocarbon molecules containing a hydroxy group -OH.

Saturated alcohols contain only ___

single bonds.

Primary Alcohol:

Hydroxy group attached to a carbon which ___

only has 1 other carbon attached to it.

Secondary Alcohol:

Hydroxy group attached to a carbon which ___

has two other carbons attached to it.

Tertiary Alcohol:

Hydroxy group attached to a carbon which ___

has three other carbons attached to it.

Order of alcohols for:

• Strength of intermolecular forces (strong to weak)

• Melting & boiling point (high to low)

1. Primary

2. Secondary

3. Tertiary

larger molecule = ___ melting & boiling points

higher

branching ___ melting & boiling points

lowers

Alcohol solubility in water

the hydroxy group of small molecules allows them to be soluble in water. Hydroxy groups are polar, therefore can form hydrogen bonds with water molecules.

miscible in water:

• methanol

• ethanol

• propanol

soluble in water to an extent:

• butanol

• pentanol

• hexanol

Alcohols with longer chains:

• ___ temporary dipoles

• ___ dispersion forces

• will form more temporary dipoles

• stronger dispersion forces

Diols and triols:

• ___ hydrogen bonds

• ___ melting and boiling points

• will form more hydrogen bonds than alcohols with one hydroxy group

• higher melting and boiling points

Secondary and tertiary:

• ___ hydrogen bonds

will form fewer hydrogen bonds between molecules

Miscible

Liquids that are indefinitely soluble

Hydrogen bonds form between the ___

hydrogen atom of the hydroxy group and the water’s oxygen atom.