Additives that are included to prevent or slow sedimentation in suspensions typically increase which property?

• A. Density
• B. Color
• C. Viscosity
• D. Solubility

Answer: (C)

To slow sedimentation, you make the liquid more resistant to flow. In a suspension, the rate at which particles settle is described by a relation where increasing the liquid’s viscosity slows the motion of particles through the medium. So additives that act as suspending agents work by increasing viscosity (thickening the gel or liquid), which reduces the settling velocity and helps keep particles evenly dispersed over time.

Density or solubility don’t directly control how fast particles fall through the liquid, and color isn’t related to sedimentation. Typical suspending agents include polymers like xanthan gum or cellulose derivatives that raise the viscosity of the suspension.