12. Which would be a better solvent for polystyrene: (a) n-pentane, (b) benzene, or (c) acetonitrile?
13. For solution to occur, the change in Gibbs free energy must be (a) 0, (b) <0, or (c) >0.
14. At which temperature will the polymer coil be larger in a poor solvent: (a) at the theta temperature, (b) below the theta temperature, or (c) above the theta temperature?
15. Describe the contents of the reaction flask 10 minutes after the polymerization of (a) reactants in a stepwise polymerization, such as dimethyl terephthalate and ethylene glycol, or, (b) monomer in chain reactions, such as isobutylene.
16. Is a Lewis acid (a) an electrophile or (b) a nucleophile?
17. Is a Lewis base (a) an electrophile or (b) a nucleophile?
18. Is the usual configuration of polymers produced by ionic chain polymerization (a) heat-to-tail or (b) head-to-head?
19. Which condition would be more apt to produce stereoregular polymers in ionic chain polymerizations: (a) high temperatures or (b) low temperatures?
Polystyrene is easily soluble in an organic solvent. Thus, benzene would be a better solvent.
12. Which would be a better solvent for polystyrene: (a) n-pentane, (b) benzene, or (c) acetonitrile? ...