Which device is used to separate two immiscible liquids and is used in liquid-liquid extraction?

• A. Graduated Cylinder
• B. Three Neck Flasks
• C. Erlenmeyer Flask
• D. Separatory Funnels

Answer: (D)

Separating immiscible liquids requires a vessel that can hold two distinct liquid layers and allow you to withdraw one layer without mixing them. A separatory funnel is designed for this purpose: after the liquids settle, the denser bottom layer can be released through a stopcock at the bottom, letting you drain it off cleanly while keeping the top layer intact. Its pear-shaped body gives space for the layers to separate, and the stopcock enables precise, controlled withdrawal—exactly what you need for a clean liquid-liquid extraction. Other glassware don’t provide this combination: a graduated cylinder measures volume, a three-neck flask is for complex reactions, and an Erlenmeyer flask can mix contents but isn’t suited to neatly separating and collecting one liquid layer without disturbance.