Question 11
Hydrogen bonds are formed when methylamine dissolves in water.
Which structure best represents a hydrogen bond between methylamine and water?
□ A
□ B
□ C
□ D
Edexcel IAL Chemistry A2 Topic 19 Organic Nitrogen Compounds
Edexcel IAL Chemistry A2 Topic 19 Organic Nitrogen Compounds
Topic 19 questions ask you to move between structures, names and reactions of amines, amides, amino acids, diazonium salts, peptides and condensation polymers.
Exam points
- Draw and classify amines, amides and amino acids from names or formulae.
- Explain amine basicity, solubility and salt formation using nitrogen lone pairs.
- Select reagents for amine preparation, diazonium chemistry, amide and peptide reactions.
- 19.1—The nomenclature of amides, amines and amino acids
- 19.2—The reactions of primary aliphatic amines (using butylamine as an example) and aromatic amines (using phenylamine as
- 19.3—Amines are miscible with water as a result of hydrogen bonding, and the reasons for the difference in basicity between
- 19.4—Understand, in terms of reagents and general reaction conditions, the preparation of primary aliphatic amines: i
- 19.5—The preparation of aromatic amines by the reduction of aromatic nitro- compounds using tin and concentrated hydrochloric
- 19.6—The reaction of aromatic amines with nitrous acid to form benzenediazonium ions, followed by a coupling reaction with phenol
- 19.7—Amides can be prepared from acyl chlorides
- 19.8—Describe: i condensation polymerisation for the formation of polyamides such as nylon and proteins ii addition
Question 12
[Maximum number: 1]
Which type of compound cannot be a monomer in the formation of polyamides?
A
amides
B
amino acids
C
diacyl chlorides
D
diamines
Question 13
[Maximum number: 2]
Alanine is an amino acid.
Question 13(a)
(a)
Which structure best represents alanine at high pH ?
□ A
□ B
□ C
□ D
[ 1 ]
Question 13(b)
(b)
Alanine is a crystalline solid at room temperature.
What are the main forces broken when alanine melts?
A
London forces
B
hydrogen bonds
C
covalent bonds
D
ionic bonds
[ 1 ]
Question 10
[Maximum number: 1]
Which reagent reacts at room temperature with methylamine, , to form the compound N-methylethanamide?
A
B
C
D
Question 11
[Maximum number: 9]
Chlorpheniramine is an amine used in the treatment of hayfever.
Question 11(a)
(a)
Deduce the classification of the labelled amine group.
[ 1 ]
Question 11(b)
(b)
The compound pyridine is used in the synthesis of chlorpheniramine.
Like many amines, pyridine is miscible with water and the solution formed is alkaline.
Explain each of these properties of pyridine.
[ 4 ]
Question 11(c)
(c)
A student suggested that the final step in the synthesis of chlorpheniramine starts with the reaction between monodesmethylchlorpheniramine and chloromethane.
Assuming the reaction is similar to that between ammonia and chloromethane, complete the mechanism for this proposed reaction.
Some of the organic structures shown have been simplified.
Include curly arrows, and any relevant dipoles and lone pairs of electrons.
monodesmethyl
chlorpheniramine
chloromethane
[ 4 ]
Question 12(a)
[Maximum number: 2]
This question is about polymers.
The diagram shows part of the structure of a polymer formed by a condensation reaction between two amino acids.
Predict the structures of the two monomers that produce this polymer.
Question 16
[Maximum number: 4]
Benzoic acid is a white crystalline solid with the structure shown.
It is found in many plants as it is an important building block for the biosynthesis of a variety of compounds, such as plant hormones and attractants for pollinators.
The role of benzoic acid in the chemical industry is also widespread and approximately 500000 tonnes are produced annually. It is used in the synthesis of many compounds, including medicines, dyes and insect repellents.
Such synthetic dyes are often classified as aryl azo dyes. These dyes have a range of vivid colours and a wide range of uses in many industries, including food and textiles. Their synthesis involves the formation of a diazonium ion. This ion then reacts with a phenol in a coupling reaction, to form the dye. The relative simplicity of the reactions involved and ready availability of starting materials make azo dyes cheap to produce.
Salts of benzoic acid, such as calcium benzoate and sodium benzoate, are used in the food industry as preservatives.
Question 16(b)
(a)
Benzoic acid can be used in the synthesis of azo dyes.
[ 4 ]
Question 16(b)(ii)
(i)
In Step 2, the 3-nitrobenzoic acid reacts to form 3-aminobenzoic acid.
State the reagents required for this reaction.
[ 1 ]
Question 16(b)(iii)
(ii)
In Step 3, the 3-aminobenzoic acid reacts with sodium nitrite and dilute hydrochloric acid, forming a diazonium ion.
State a temperature at which this reaction should take place, giving one reason for your answer.
[ 2 ]
Question 16(b)(iv)
(iii)
Draw the structure of the azo dye formed when the diazonium ion reacts with phenol.
[ 1 ]