Module 6 - Keywords

Question 1

Kekulé model

Answer 1

The model of benzene which shows alternating and fluctuation single and double bonds

Question 2

Delocalised electrons

Answer 2

Electrons within a species which are not associated with a particular atom or bond

Question 3

Hydrogenation

Answer 3

Adding hydrogen

Question 4

Electrophilic substitution

Answer 4

Replacement of hydrogen on a benzene ring

Question 5

Halogen carrier

Answer 5

Iron/iron halide/aluminium halide - used in Friedel-Crafts reaction

Question 6

Fridel-Craft

Answer 6

A reaction which forms a C-C bond to a benzene ring

Question 7

Phenol

Answer 7

Benzene ring with an OH group attached to the ring

Question 8

Cyanide

Answer 8

CΞN group

Question 9

Electron donating groups

Answer 9

Electron rich groups like OH and NH₂ which direct towards positions 2 and 4 on the benzene ring

Question 10

Electron withdrawing groups

Answer 10

Electron poor groups like NO₂ which direct towards position 3 on the benzene ring

Question 11

Nucleophilic addition

Answer 11

Mechanism for the reaction of carbonyls with HCN and NaBH₄

Question 12

2,4-DNPH

Answer 12

2,4-dinitrophenolhydrazine, forms an orange ppt on reaction with carbonyls the characteristic melting point of which can be used to identify the aldehyde or ketone

Question 13

Tollens’ reagent

Answer 13

Ammoniacal silver nitrate used in the silver mirror test for an aldehyde

Question 14

Esterification

Answer 14

Reaction of an alcohol with a carboxylic acid in the presence of an acid catlyst to make esters

Question 15

Carboxylate

Answer 15

A salt of a carboxylic acid

Question 16

Acid anhydride

Answer 16

A compound with 2 acyl groups bonded to the same oxygen atom

Question 17

Acyl chloride

Answer 17

Homologous series with the functional group COCl

Question 18

Primary amine

Answer 18

The amine formed when only one of the hydrogens on an ammonia has been replaced by an R group RNH₂

Question 19

Secondary amine

Answer 19

The amine formed when 2 of the hydrogens on an ammonia has been replaced with an R group, R₂NH

Question 20

Amine

Answer 20

The compound formed when one or more of the hydrogens on an ammonia has been replaced with an R group

Question 21

Nitroarenes

Answer 21

An arene (e.g. benzene) which has had one of its hydrogens replaced by an NO₂ (e.g. nitrobenzene)

Question 22

α-amino acid

Answer 22

A compound with the general formula RCH(NH₂)COOH

Question 23

Optical isomers

Answer 23

Stereoisomers which form non superimposable mirror images due to the oresence of chiral centre(s)

Question 24

Chiral centre

Answer 24

A carbon which has 4 different groups attached to it

Question 25

Polyester

Answer 25

A polymer (a chain of repeating units) where the individual units are held together by ester linkages -COO-

Question 26

Polyamide

Answer 26

A polymer (a chain of repeating units) where the individual units are geld togetger by amide linkages -CONH-

Question 27

Addition polymerisation

Answer 27

Small unsaturated monomers (monomers with carbon to carbon double bonds) join up by the opening of the doubel bond to allow them to join up to form a long carbon chain

Question 28

Condensation polymerisation

Answer 28

Polymers formed through a condensation reaction. Molecules join together, losing small molecules as by-products such as water or methanol

Question 29

Monomer

Answer 29

Molecules that react together to form polymers

Question 30

Nitriles

Answer 30

Molecules which contain the -CΞN group

Question 31

Nucleophilic substitution

Answer 31

The replacement of an electronegative atom/group with a nucleophile

Question 32

Nucleophilic addition

Answer 32

An addition reaction where a chemical compound with an electron deficient or electrophilic π bond, reacts with a nucleophile, to create 2 new single bonds

Question 33

Recrystallisation

Answer 33

A method used to purify an organic solid. The organic compound is dissolved in the minimum volume of warm solvent and the sample recrystallises as it cools. The impurities must be more soluble in the solvent than the required product