Which of the following statements about fractional distillation are true. a. For good separation by distillation the volume of liquid condensing back to the pot should be lower than the volume of liquid distilling off. b. The lower the HETP (height equivalent to a theoretical plate) of the fractionating(packed) column the more efficient it is at separation of components. c. Can ideally separate mixtures with comparable volatilities small BP differences. d. The distillation process involves several concurrent vaporization-condensation cycles. Continual change in boiling temperature is observed a:.