Can colloidal suspensions be separated by filtration?

• A. Yes, but only if a vacuum filter is used.
• B. No, because colloidal particles dissolve completely in the solvent.
• C. No, because the particles in a colloidal suspension are too small to be retained by standard filter paper.
• D. Yes, because filtration can separate all types of mixtures, including colloids.

Answer: (C)

Verified step by step guidance

1. Understand the nature of colloidal suspensions: Colloids consist of particles that are intermediate in size between true solutions and suspensions, typically ranging from 1 nm to 1000 nm in diameter.
2. Recall the principle of filtration: Filtration separates mixtures based on particle size, where particles larger than the filter pores are retained, and smaller particles pass through.
3. Analyze why standard filtration does not work for colloids: Since colloidal particles are very small, they can pass through the pores of standard filter paper, meaning filtration cannot effectively separate them.
4. Consider alternative separation methods: Techniques like centrifugation or ultrafiltration, which can separate smaller particles, are more suitable for colloids rather than simple filtration.
5. Conclude that the correct statement is: 'No, because the particles in a colloidal suspension are too small to be retained by standard filter paper.'