Polyvinyl chloride (PVC) is one of the most commercially important polymers (Table 12.5)...

Polyvinyl chloride (PVC) is one of the most commercially important polymers (Table 12.5). PVC is made by addition polymerization of vinyl chloride (C₂H₃C1). Vinyl chloride is synthesized from ethylene (C₂H₄) in a two-step process involving the following equilibria:

The product of Equilibrium 1 is 1,2-dichloroethane, a compound in which one Cl atom is bonded to each C atom. (a) Draw Lewis structures for C₂H₄C₁₂ and C₂H₃Cl. What are the C—C bond orders in these two compounds? (b) Use average bond enthalpies (Table 8.4) to estimate the enthalpy changes in the two equilibria. (c) How would the yield of C₂H₄C₁₂ in Equilibrium 1 vary with temperature and volume? (d) How would the yield of C₂H₃Cl in Equilibrium 2 vary with temperature and volume? (e) Look up the normal boiling points of 1,2-dichloroethane and vinyl chloride in a sourcebook, such as the CRC Handbook of Chemistry and Physics. Based on these data, propose a reactor design (analogous to Figure 15.12) that could be used to maximize the amount of C₂H₃Cl produced by using the two equilibria.