Q1: For a cold dilute feed to produce thick viscous liquor, backward feeding as compared to forward feeding results in

ANS:A - increased economy

In the context of evaporators, backward feeding refers to feeding the coldest feed into the last effect of the evaporator series, while forward feeding involves introducing the coldest feed into the first effect. If backward feeding compared to forward feeding resulted in increased economy, it would imply that backward feeding is more efficient in terms of energy usage or resource utilization. However, this statement contradicts the typical understanding in evaporator operations. Generally, forward feeding is considered more energy-efficient than backward feeding because it allows for better utilization of heat across the evaporator effects. Forward feeding ensures that the coldest feed is exposed to the highest temperature difference in the first effect, resulting in more efficient heat transfer and energy utilization. As a result, forward feeding is often preferred in evaporator designs to maximize energy efficiency and overall process economy. Therefore, in the context of evaporators, it's more accurate to say that backward feeding compared to forward feeding typically results in decreased economy, as explained in the previous response.