11.2 Nomenclature - naming organic compounds

Question 1

What is a functional group?

Answer 1

Atom or group of atoms in an organic molecule which is responsible for the characteristic reactions of that molecule.

Question 2

Alkane

Answer 2

C-C single bonds, bonded to hydrogens

Question 3

Alkene

Answer 3

C=C double bond eg ethene

Question 4

Alcohol

Answer 4

Characterised by the hydroxy, -OH group eg propan-1-ol

Question 5

Carboxylic Acid

Answer 5

Characterised by the carboxyl group - COOH. The functional group is always at the end of the molecule

Question 6

Acid anhydrides

Answer 6

Formed when 2 carboxylic acids react together and water is removed, hence the hydride.

Eg ethanoic anhydride

O O
|| ||
/ \ O / \

Question 7

Halegenoalkane

Answer 7

R-X

Alkyl group, where the X is replaced with a halogen

Eg chloroethane

Question 8

Aldehyde

Answer 8

O
||
R - C - H

Has a carbon double bonded to an oxygen and single bond to a hydrogen. Functional drop can only be at the end of the molecule.

Question 9

Ketone

Answer 9

Carbon Double bonded to an oxygen, with two single bonds to alkyl groups. C=O bond found in the middle of the molecule - RCOR

O
||
R - C - R

Question 10

Amine

Answer 10

A carbon atom bonded to nitrogen. Amines can either be primary secondary or tertiary. Eg ethylamine, trimethylamine.

R - NH2

NH
/ \
R R

Question 11

Amide

Answer 11

A functional group consisting of a carbonyl group bonded to a nitrogen

 O
 || R - C - R’ - R’’

Question 12

Nitrile

Answer 12

Alkyl or aromatic group attached to a carbon triple bond nitrogen eg propanenitrile

     _ R-C   _ N
     _

Question 13

Acyl Chlorides

Answer 13

Have an alkyl or aromatic group attached to a carbonyl functional group plus a single bond to a chlorine - eg ethanoyl chloride

 O 
|| R - C - Halogen

Question 14

Ester

Answer 14

Have a carbon double bonded to an oxygen and single bonded to an oxygen. Alkyl groups either side of the functional group.

Eg ethyl ethanoate

Question 15

Suffix for alkanes

Answer 15

-ane

Question 16

Suffix for alkenes

Answer 16

-ene

Question 17

Suffix for halegonealkanes

Answer 17

None

Question 18

Suffix for alcohols

Answer 18

-ol

Question 19

Suffix foraldehydes

Answer 19

-al

Question 20

Suffix for ketones

Answer 20

-one

Question 21

Suffix for carboxylic acids

Answer 21

-oic acid

Question 22

What is a homologous series

Answer 22

A homologous series is a family of organic compounds with the same function group but different carbon chain lengths.

Question 23

Characteristics of a homologous series

Answer 23

• same general formula
• each member of the series differs by CH2
• the length of the carbon chain has little effect on the chemical reactivity of the functional group
• the length of the carbon chain affects physical perspectives (eg melting/boiling points) - intermolecular forces increase
• chain branching generally reduces melting points because the molecules uses pack together less well