As the reflux ratio, in a continuous counter-current extraction is increased, the number of stages

ANS:B - decrease

In a continuous counter-current extraction system, as the reflux ratio is increased, the number of stages generally: Decreases. The reflux ratio is defined as the ratio of the reflux (liquid returning from the condenser) to the distillate (liquid product). Increasing the reflux ratio increases the amount of liquid returned to the column, which enhances separation efficiency. As a result, fewer stages are required to achieve the desired separation, leading to a decrease in the number of stages. Conversely, if the reflux ratio is decreased, more stages would be needed to achieve the same level of separation, as less liquid is returned to the column, leading to a decrease in separation efficiency. Therefore, in continuous counter-current extraction systems, increasing the reflux ratio typically leads to a decrease in the number of stages required.