Filtration is the method used to separate solids from fluids by interposing a medium through which only the fluid can pass. Which term describes this process?

• A. Filtration
• B. Sedimentation
• C. Extraction
• D. Distillation

Answer: (A)

Filtration uses a porous barrier to separate solids from a liquid by letting only the fluid pass through while the solid is held back by the pore structure. As the liquid flows through the filter, solid particles are trapped, forming a residue on or within the filter and yielding a clarified liquid known as the filtrate. The effectiveness depends on the pore size and can be enhanced by applying gravity or suction to drive the flow. This approach is distinct from sedimentation, which relies on solids settling out under gravity without a filter; extraction, which involves transferring a component into another solvent; and distillation, which separates components based on boiling points. Coffee filtration is a common everyday example.