Which one of the following apparatus is used for separating benzene and water mixture ?

The correct option is Option C (Separating funnel). This laboratory apparatus is specifically designed to separate two immiscible liquids—liquids that do not dissolve in each other and instead form distinct layers based on their densities.

• Benzene and Water: Benzene is a non-polar organic compound, while water is a polar solvent. Because they are immiscible, they form two layers; benzene, being less dense (approx. 0.87 g/cm³), floats on top of the water (approx. 1.00 g/cm³).
• Mechanism: The mixture is poured into the separating funnel and allowed to settle. The stopcock at the bottom is then opened to carefully drain the denser water layer into a separate container, leaving the benzene in the funnel.
• Other Options: Round bottom and conical flasks are primarily used for mixing, heating, or storage. The Dean and Stark apparatus is used for determining water content via azeotropic distillation, which is a more complex process than simple physical separation.