Objectives Concepts: –Functional group, alkane, alkene, alkyne, alcohol, carbonyl, aldehyde, ketone, carboxylic acid, ether, ester, amine, amide, halogenoalkane –Primary alcohol, secondary alcohol, tertiary alcohol, primary amine, secondary amine, tertiary amine, Skills: –Draw and state names of the compounds containing up to six carbon atoms with the following functional groups: aldehyde, ketone, carboxylic acid, alcohol, amide, amine, ester and halogenoalkane.
Functional Groups As has already been indicated, alkanes are relatively unreactive. For an organic molecule to be reactive it needs something additional. A site of reactivity in an organic molecule is called a functional group. C=C double is a functional group. Other functional groups contain elements other than C or H, notably O, N and Cl.
Functional Group A functional group could be an atom or a group of atoms within a molecule that is responsible for its characteristic chemical reactions.
alkanes Only carbon and hydrogen All single bonds Their names end with -ane CCH H H H H H Ethane
alkenes Only carbon and hydrogen A carbon to carbon double bond Their names end with -ene CC HH H H Ethene
alkynes Only carbon and hydrogen A carbon to carbon triple bond Their names end with -yne C C H H Ethyne
alcohols Only one oxygen Has an O-H group Can be classified as 1º/2º/3º according to position of O-H group on carbon skeleton They are named as alkanol C C HH H HH HO Ethanol
Primary alcohol C C HH H HH HO CC HO H HH HC H H H CC HO H H3H3 H HC H H H C Secondary alcohol Tertiary alcohol
aldehydes Only one oxygen Has a C=O group C=O group is at the end of the carbon chain, so is next door to a hydrogen atom They are named as alkanal CC H H O H H Ethanal
ketones Only one oxygen Has a C=O group C=O group is not at the end of carbon chain, so is next door to 2 carbons They are named as alkanone CC H H O H H C H H Propanone
esters Has 2 oxygens One oxygen is part of a C=O bond, the other is next door, sandwiched between two carbons. They are named as Alkylalkanoate CC H H O O H C H H H Methylethanoate
carboxylic acids Has 2 oxygens Has O-H and C=O groups on the same carbon atom This -COOH group has to be at the end of a carbon chain. They are named as alkanoic acid CC H H O O H H Ethanoic acid
ether Has 1 oxygen No O-H or C=O group The oxygen is sandwiched between two carbon atoms Their names end with -ether CC H HO H CH H H H H Ethylmethylether
Amines Contain Nitrogen Has an –NH 2 group Can be classified as 1º/2º/3º according to the number of carbon atoms connected to the N They are named as alkyl amine Ethylamine C C HH H HH HN H
Amide Has NH 2 and C=O groups on the same carbon atom They are named as alkanamide CC H H O H Ethanamide HN H
Haloalkanes Have the general formula R-X where R is an alkyl group and X is a halogen They are named as haloalkanes CCCl H H H H H Chloroethane