Which of the following best determines whether a mixture is classified as a suspension or a colloid?

• A. The temperature at which the mixture is formed
• B. The size of the dispersed particles in the mixture
• C. The pH of the mixture
• D. The color of the dispersed phase

Answer: (B)

Verified step by step guidance

1. Understand the definitions of suspension and colloid: A suspension is a heterogeneous mixture where the dispersed particles are large enough to eventually settle out, while a colloid has smaller particles that remain evenly distributed without settling.
2. Recognize that the key difference between suspensions and colloids lies in the size of the dispersed particles. Suspensions typically have particles larger than 1000 nanometers, whereas colloids have particles ranging from about 1 to 1000 nanometers.
3. Note that other factors such as temperature, pH, or color do not fundamentally determine whether a mixture is a suspension or a colloid, although they may affect stability or appearance.
4. Therefore, to classify a mixture as a suspension or a colloid, focus on measuring or estimating the size of the dispersed particles.
5. Summarize that the best criterion for classification is the particle size, because it directly influences the mixture's behavior, such as settling and light scattering.