Unit 2 – Day 7Functional Groups

Functional Groups

• Functional groups are groups of atoms that affect the way hydrocarbons behave.

• They replace a hydrogen on the hydrocarbon.

MethaneMethanol

Organic Families

• If hydrocarbons have the same functional groups, they tend to behave the same way.

• For this reason, organic families of chemicals are grouped based on functional groups.

Organic FamiliesFunctional Group Family Name Examples

-OHHydroxyl Group

Alcohols Rubbing AlcoholGrain Alcohol

-COOHCarboxyl Group

Carboxyllic Acids Vinegar

-C=OCarbonyl Group

Ketones (mid)Aldehydes (end)

FormaldehydeAcetone

-NH2

Amino GroupAmines Antihistamines,

Amino Acids

Organic FamiliesFunctional Group Family Name Examples

-O-Ether

Ethers Diethyl ether

Ester Esters Flavours and Odours

C=C Alkenes Ethylene

CC Alkynes Acetylene

Alcohols

• All alcohols have the hydroxyl group.• This is a polar covalent bond, which allows

alcohols to be volatile liquids.• They are all toxic and flammable.

Naming Alcohols

• We name alcohols using the same prefix and suffix system used for hydrocarbons.

• The prefix indicates the number of carbons.• All alcohols end in “–anol”• We use a number to indicate which carbon

has the hydroxyl group.

Examples:

• CH3-CH2OH

• CH2OH-CH2-CH2-CH3

• Draw 2-pentanol

Carboxylic Acids

• Carboxylic acids all contain the carboxyl group.• This group easily loses its hydrogen atom in

water, which makes these molecules acidic.• They are corrosive like other acids, and also

volatile like organic compounds.• One example is vinegar (acetic acid)

Naming Carboxylic Acids

• We name acids using the same system.• The prefix indicates the number of carbons.• The suffix for all carboxylic acids is “-anoic

acid”.• The carboxyl group can only go on the end

carbon, so no number is required.

Examples:

• CHOOH

• CH3CH2COOH

• Draw butanoic acid