Q1: A dilute aqueous solution is to be concentrated in an evaporator system. High pressure steam is available. Multiple effect evaporator system is employed, because

ANS:B - total amount of vapor produced per Kg of feed steam in a multiple effect system is much higher than in a single effect.

The correct reason for employing a multiple effect evaporator system when concentrating a dilute aqueous solution with high pressure steam available is: b) The total amount of vapor produced per kg of feed steam in a multiple effect system is much higher than in a single effect. In a multiple effect evaporator system, the vapor generated in one effect is used as the heating medium in the subsequent effects. This cascading of effects allows for more efficient utilization of the latent heat of vaporization of the steam. As a result, the total amount of vapor produced per unit of feed steam is significantly higher in a multiple effect system compared to a single effect system, making it a more efficient choice for concentrating dilute solutions.