Indiana Pesticide Applicator Core Practice Exam

What characterizes a suspension in pesticide terms?

1. A solid dissolved in a liquid

2. A mixture of liquid and solid particles

3. A homogenous blend of two liquids

4. A mixture that includes only gases

The correct answer is: A mixture of liquid and solid particles

A suspension in pesticide terms is characterized by a mixture of liquid and solid particles. In this context, the solid particles are dispersed within the liquid but are not completely dissolved, which is a key characteristic of suspensions. Over time, the solid particles may settle at the bottom of the container if left undisturbed, which differentiates them from solutions where the solid is completely dissolved and not visible. This understanding is crucial for pesticide applicators because suspensions can be effective for delivering active ingredients that may not dissolve well in the solvent. Applying proper agitation before use ensures an even distribution of the active ingredient throughout the mixture, which is essential for achieving optimal efficacy. In contrast, a solid dissolved in a liquid refers to a solution, not a suspension. A homogenous blend of two liquids describes an emulsion rather than a suspension. Lastly, a mixture that includes only gases does not apply to the definition of a suspension, as it does not involve a liquid medium with solid particles. Understanding these differences is vital for proper pesticide application and management.