Q1: Flash distillation is

ANS:B - used for multicomponent systems like crude refining.

Flash distillation is most useful for handling binary systems. It's a type of distillation process where a liquid mixture is partially vaporized and then immediately condensed to separate it into its components. This process is particularly effective for separating a binary mixture into its components based on their volatility. In flash distillation, the liquid mixture is heated to a temperature where the more volatile component vaporizes while the less volatile component remains in the liquid phase. The mixture is then fed into a vessel (the flash drum) at a lower pressure, causing the vaporization of some of the liquid. The vapor and liquid phases are allowed to separate, and the vapor is condensed back into liquid form. This process is different from simple distillation, where the entire liquid mixture is vaporized and condensed in a single stage. Flash distillation is particularly advantageous for binary systems because it allows for separation with fewer stages and lower energy consumption compared to more complex distillation processes like differential distillation, which is used for separating mixtures with multiple components based on their boiling points.