Question

Separation of liquids from solids by application of pressure is known as:

• A. Extraction
• B. Expression
• C. Rendering
• D. Leaching

Hint:

To remember: "Expression" is like "pressing." You apply pressure to express the liquid out. "Leaching" is like "soaking" where a solvent does the work.

Answer 1

The Correct Option is B

Separating liquid from a solid using pressure alone, without any solvent involved, is a purely mechanical operation. This is what happens in a screw press crushing oilseeds or in squeezing juice out of grapes or sugarcane, and this pressure driven squeezing process is called expression. Leaching instead uses a solvent to dissolve out the liquid rather than mechanical force. Since the question specifically mentions pressure, the correct term is expression.