Q1: __________ extractor uses centrifugal force for separating the two phases.

ANS:C - Podbielniak

The Podbielniak extractor, named after its inventor Zygmunt J. F. Podbielniak, is a type of liquid-liquid extractor used for the separation of immiscible liquids or the purification of liquid mixtures. It operates on the principle of centrifugal force to enhance the separation process. The design of the Podbielniak extractor typically consists of a vertically oriented column with multiple stages or trays arranged along its length. Each stage comprises two perforated plates stacked vertically with holes of decreasing size from top to bottom. The liquid mixture to be separated or purified is introduced at the top of the column, while the extracting solvent or phase is introduced at the bottom. As the mixture flows downward through the column, the perforated plates on each stage create a series of liquid-liquid contact zones. The immiscible liquids come into contact and undergo mass transfer across the perforated plates. Centrifugal force, generated by the rotation of the column, aids in the separation by pushing the heavier phase (typically the aqueous phase) outward toward the column wall, while the lighter phase (usually the organic phase) moves inward towards the column axis. This differential movement helps in achieving efficient phase separation. The extracted or purified liquid collects at the bottom of the column and is removed from the system, while the remaining liquid mixture exits the top of the column. The efficiency of the separation process in a Podbielniak extractor depends on factors such as the design of the column, the properties of the liquids involved, and the operating conditions. Podbielniak extractors find applications in various industries, including pharmaceuticals, chemicals, food processing, and petroleum refining, for tasks such as solvent extraction, purification of organic compounds, separation of valuable products from process streams, and wastewater treatment. They offer advantages such as high efficiency, compact design, scalability, and the ability to handle a wide range of liquid-liquid systems.