To mix white petroleum and purified water together, what should be used?

• A. Preservatives
• B. Emulsifiers
• C. Thickening agents
• D. Colorants

Answer: (B)

Emulsifiers are used to mix oil and water. White petroleum is an oil and purified water are immiscible, so they don’t form a stable blend on their own. An emulsifier has both water-loving and oil-loving parts, so it sits at the oil–water interface and reduces interfacial tension, creating a stable dispersion (an emulsion) where droplets of one phase are dispersed in the other. That’s why this option is the right choice. Preservatives, colorants, and thickening agents don’t enable true mixing of immiscible liquids—preservatives protect, colorants add color, and thickening agents raise viscosity but don’t stabilize an oil–water blend.