Which term describes the density comparison of a liquid to water at the same temperature?

• A. Vapor density.
• B. Flash point.
• C. Specific gravity.
• D. Surface to mass ratio.

Answer: (C)

Specific gravity is the density of a liquid compared with the density of water at the same temperature. It’s a dimensionless ratio, calculated as density_liquid divided by density_water. This tells you how heavy the liquid is relative to water and whether it will sink or float on water. If the value is greater than 1, the liquid is denser than water; if less than 1, it’s lighter.

Vapor density describes the density of a vapor relative to air, not a liquid’s density relative to water. The flash point is the temperature at which a liquid’s vapors can ignite, unrelated to density. The surface-to-mass ratio isn’t a standard measure used for comparing densities.