Before adding powder to the vehicle, which step helps achieve a uniform distribution in a suspension?

• A. Dry blending without liquid
• B. Heating the powder
• C. Wetting the powder
• D. Centrifugation

Answer: (C)

Wetting the powder with the vehicle aids uniform dispersion by coating the particle surfaces and allowing liquid to penetrate the particle pores. When powder is dry, particles tend to stick together due to cohesive forces and trapped air, forming agglomerates that don’t mix evenly. Wetting reduces these forces and creates a smooth slurry, so each particle can be distributed more evenly once the powder is added to the suspension. Heating the powder, dry blending, or centrifugation don’t promote this initial, even dispersion in the same way; heating could alter the powder, dry blending leaves clumps, and centrifugation is a separation step rather than a dispersion step.