AQA A2 Chemistry 28 Amines Kerboodle Answers

This page contains the AQA A2 Chemistry C28 Amines Questions and kerboodle answers for revision and understanding.This page also contains the link to the notes and video for the revision of this topic.
 
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C28.1 Introduction to amines: Page No. 187

1 Secondary 2 Ethylpropylamine
4 A gas

5 lt has the same value of Mr as ethylamine, which is a gas. 28.2 The properties of amines as bases: Page No. 189

1 a (CH3)2NH + HCl→ (CH3)2NH2++ Cl– b Dimethylammonium chloride 2 a It will dissolve, that is, the oily drops will disappear to give a colourless solution. b The oily drops will re-appear.

3 Stronger, as it has two electron-releasing alkyl groups. 28.3 Amines as nucleophiles and their synthesis: Page No. 193

1 Because secondary and teniary amines (and quaternary ammonium salts) may be formed as well. 2 a b (C2H5)2NH; (C2H5)3N; (C2H5)4N+Cl– Banner 2

Practice questions: Page No.  194-195

1 (a) Dimethylamine (b) ( Nucleophilic substitution (c) Quaternary ammonium salt
  • Surfactant / detergent / fabric softener or conditioner/ hair conditioner
2 (a) Sn or Fe/HCl
  • Sn or Fe/H2SO4
  • OR H2/Ni can be used as the reducing agent
(b) (c) 3 (a) Nucleophilic substitution (b) (c) There is a lone pair (on N);
  • R group increases electron density on N / has positive inductive effect
(d) CH3CH2N(CH3)2 4 (a) CH3CH2CH2Br (b) CH3CH2CN (c) Nucleophilic substitution or from CH3CH2CH2Br gives less pure produce because further substitution occurs The impurity can be any one of 5 (Nucleophilic) addition-elimination
  • Allow wrong amine in M1 but penalise in M3
  • Allow C3H7 in M3
  • Minus sign on NH3 loses M1 (but not M4 if NH3 also shown here)
  • N-propylethanamide must be this name even if wrong amine used.
(b) (i) 6 (a) (nucleophilic) addition-elimination N-ethylpropanamide (b) CH3CN or ethan(e)nitrile or ethanonitrile For each step wrong or no reagent loses condition mark Step 1 Cl2 uv or above 300 °C Step 2 KCN aq and alcoholic (both needed) Step 3 H2/Ni or LiAlH4 or Na/C2H5OH 7  (a) Phenylamine accepts a proton/H+ (b) It is an ionic salt so it dissolves in a polar solvent like water. Banner 3

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