Compound W, CH2=CHCN, is used to make an addition polymer which is present in carbon fibres.

1. (a)Draw one repeat unit of the addition polymer of W.[1]
2. (b)CH3CHO is used in a two-step synthetic route to form W, as shown in Fig. 6.1. In step 1, CH3CHO is heated with HCN in the presence of KCN. [Figure 6.1] CH3CHO step 1 CH3CH(OH)CN step 2 CH2=CHCN W
3. (b)(i)Name the mechanism for the reaction in step 1 in Fig. 6.1.[1]
4. (b)(ii)Complete Fig. 6.2 to show the mechanism for the reaction in step 1. Include all products, charges, dipoles, lone pairs of electrons and curly arrows, as appropriate. [Figure 6.2 with partial diagram][3]
5. (b)(iii)Suggest a suitable reagent and conditions for step 2 in Fig. 6.1.[1]
6. (b)(iv)Fig. 6.3 shows the infrared spectrum of W, CH2=CHCN. [Figure 6.3] Use Table 6.1 to identify the bonds responsible for the absorptions marked S and T on Fig. 6.3. S T[1]
7. (c)Molecules of W, CH2=CHCN, do not show stereoisomerism.
8. (c)(i)Describe stereoisomerism.[1]
9. (c)(ii)Describe the two essential features of an alkene molecule that cause it to show geometrical stereoisomerism.[2]
10. (d)Molecules of CH3CH(OH)CN exist as a pair of optical isomers. Draw three-dimensional diagrams in the boxes to show the optical isomers of CH3CH(OH)CN. isomer 1 isomer 2[1]
11. (e)Propanenitrile is heated with hydrogen gas and a platinum catalyst. The only product is propylamine. Construct an equation for this reaction.[1]
12. (f)Propylamine can also be formed in a two-step synthesis from propan-1-ol, as shown in Fig. 6.4. [Figure 6.4] CH3CH2CH2OH step 1 SOCl2 CH3CH2CH2Cl step 2 CH3CH2CH2NH2
13. (f)(i)Name the type of reaction in step 1 in Fig. 6.4.[1]
14. (f)(ii)Identify the reagent and conditions for step 2 in Fig. 6.4.[2]

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