ANS:B - Solvent extraction

Selectivity is an important parameter in solvent extraction. Here's why:

• Solvent extraction is a unit operation used to separate components from a liquid mixture based on their differential solubilities in two immiscible phases: a solvent phase and a feed phase.
• Selectivity in solvent extraction refers to the ability of the solvent to preferentially extract one component from the feed phase over others. Higher selectivity means that the solvent can more effectively separate the desired component from the mixture while leaving other components behind.
• The selectivity of the solvent is crucial in determining the efficiency and effectiveness of the separation process. It directly influences the purity of the extracted component and the yield of the desired product.
• Engineers and scientists optimize the selectivity of the solvent by choosing a suitable solvent with specific chemical properties that favor the extraction of the desired component while minimizing the extraction of undesired components.