Dilution is used to achieve what effect?

• A. To increase the concentration of contaminants
• B. To neutralize hazardous substances
• C. To reduce concentration by adding water
• D. To remove contaminants from large numbers

Answer: (C)

Dilution lowers how concentrated a contaminant is by adding solvent, typically water. By spreading the same amount of contaminant over a larger volume, its concentration per unit of volume drops, which helps reduce hazards and makes handling, sampling, or measurement safer and more feasible. That’s exactly what the option describes: reducing concentration by adding water.

It doesn’t increase concentration, nor does it chemically neutralize the substance or remove contaminants. Those would be separate actions (increasing concentration, neutralization, or removal).