1.
H H H C C H H C C H C H H C H H
Compound A Compound A is an intermediate compound found in a production plant attempting to synthesise n-hexane. a) List three physical properties of alkynes. b) Give the IUPAC name of compound A. [3 marks] [2 marks]
c) There are several ways to form the final product from Compound A. An operator has decided to use Pt catalyst to react with Compound A. Write the complete chemical reaction equation. [3 marks] d) The quality assurance manager of the production plant found out that the method in (c) is not very efficient and has decided to look for an alternative pathway to produce nhexane. He suggested on forming an intermediate step of alkene, which later undergoes reduction reaction to form n-butane. Propose two reaction pathways to produce n-butane, writing the complete chemical reaction equations. [10 marks] e) n-hexane is a type of alkane. List three physical properties of alkane. [3 marks] …show more content…
f) n-hexane undergoes halogenation with Cl2.
List four possible haloalkanes that can be formed from this reaction. [4 marks] [TOTAL: 25 marks]
2. C5H12 is an alkane. It can be present in three different forms of constitutional isomers. a) Name and draw the three constitutional isomers of C5H12. [6 marks]
b) Describe the reaction steps of C5H12 when it reacts with Cl2 in the presence of UV light, giving an example for each reaction steps. [8 marks]
c) One of the product that can be formed from (b) is 2,3-dichloropentane. Draw the structure of this compound. [2 marks] d) 2,3-dibromopentane can be formed via halogenations of an alkene. Name the alkene required. [2 marks]
e) Write the complete chemical reaction equation for the halogenations reaction in (d). [3 marks] f) The alkene formed in (d) is synthesized from 2-pentyne. Suggest the methods required to form (i) cis-alkene and (ii) trans-alkene. [4 marks] [TOTAL: 25
marks]
3. Determine the aromaticity of the following compounds based on Hückel’s Rule. a) (i) C10H10 (ii) C12H12 (iii) C8H8 [6 marks] b) Benzene (C6H6) is an aromatic compound. Describe the bromination (Br2) reaction of benzene in the presence of FeBr3 catalyst. [8 marks] c) Describe Friedel-Crafts alkylation process to form ethylbenzene. d) Describe Friedel-Crafts acylation process to form acetylbenzene. [6 marks] [5 marks] [TOTAL: 25 marks]