In liquid-liquid extraction, which term describes the phase that is not the extract and remains after extraction?

• A. Extract
• B. Raffinate
• C. Liquid phase
• D. Solvent-rich phase

Answer: (B)

In liquid-liquid extraction, two immiscible liquid phases form and a solute distributes between them. The phase that ends up carrying most of the solute is called the extract. The phase that remains after separation and contains little of the solute is the raffinate. So, the raffinate is the phase not enriched by the extract—it's what stays behind after the transfer. For example, when a solute is moved from water into an immiscible organic solvent, the organic layer is the extract and the water layer left behind is the raffinate. The term raffinate specifically means the phase that remains after extraction, distinguishing it from the extract.