ANS:A - 1

In liquid-liquid extraction, the "plait point" refers to a specific condition where the system reaches a balance between the phases involved. This typically occurs when the system has achieved equilibrium, and the number of phases present at this point depends on the specific extraction system and conditions. In most cases, liquid-liquid extraction involves two immiscible liquid phases: the extracting solvent and the feed solution. However, at the plait point, additional phases may form due to the complex interactions between the components involved. So, the correct answer is: 3. At the plait point, there can be three phases present in the system due to the equilibrium between the extracting solvent, feed solution, and an intermediate phase.