Q1: Reboiler is considered as one theoretical plate, because

ANS:A - of the assumption that vapour and liquid leaving the reboiler are in equilibrium.

A reboiler is considered as one theoretical plate because of the assumption that the vapor and liquid leaving the reboiler are in equilibrium. In distillation processes, the reboiler is responsible for supplying heat to the bottom of the column, causing the liquid to vaporize and rise up through the column. The vapor leaving the reboiler is typically richer in the more volatile components, while the liquid leaving the reboiler is typically richer in the less volatile components. The assumption of equilibrium between the vapor and liquid leaving the reboiler simplifies the analysis of the distillation process. It allows for the concept of theoretical plates to be applied, where each theoretical plate represents a stage of equilibrium between the vapor and liquid phases. While the other options provided may be aspects of how a reboiler operates in a distillation column, the main reason why a reboiler is considered as one theoretical plate is because of the assumption of equilibrium between the vapor and liquid leaving the reboiler.