Which statement correctly describes polar solvent fuels in relation to water?

• A. They are hydrophobic and float on water.
• B. They are hydrophilic and need alcohol-resistant foam.
• C. They evaporate quickly and do not require special foam.
• D. They mix with water to form a gel.

Answer: (B)

Polar solvent fuels are hydrophilic and water-miscible, meaning they readily mix with water rather than forming a separate layer. This behavior defeats conventional hydrocarbon foams, which rely on a stable oil layer to blanket the fire. Alcohol-resistant foam is designed to resist dissolution by these polar solvents and to form a protective film on the fuel surface even when water and polar solvents are present. That combination—being water-loving and requiring a foam that can withstand polar solvents—makes the statement correct.

Other ideas don’t fit: nonpolar fuels tend to separate and float on water, not polar solvents; polar solvents can evaporate, but standard foams still struggle unless AR foam is used; and mixing with water doesn’t typically form a gel, so AR foam is still needed to manage the foam in the presence of polar solvents.