(a)

(i) Substitution = 4

(ii) Addition reaction = 6 and 5

(iii) Elimination reaction = 2 and 7

(b)

(i) H₂/Ni

(ii)

Bonds formed: C-H, C-C, C-O, O-H

(c) Ethanol is highly soluble in water due to hydrogen bonding.

(d)

(i) Compound X: Chloroethene

(ii) In conversion 7 the geometry changes from tetrahedral geometry to planar geometry due to the double bond.

(iii) Two repeating units of PVC

(e) Conversion 6 is an addition reaction.

Step 1: Polarisation — as the Cl₂ moves towards the double bond of ethene it becomes polarised.

Step 2: Heterolytic fission — the Cl₂ molecule splits into ions Cl⁺ and Cl^-

Step 3: Carbonium ion formation — the Cl^- ion forms a covalent bond with one of the carbon atoms, leaving the other carbon with a positive charge.

Step 4: Ionic addition — the carbonium ion is then attacked by the Cl^- ion forming 1,2 chloroethane.