What is specific gravity?

• A. The weight of a liquid as compared to water
• B. The color of a liquid
• C. The viscosity of a liquid
• D. The vapor pressure of a liquid

Answer: (A)

Specific gravity is the ratio that compares how heavy a liquid is to water. It’s the density of the liquid divided by the density of water at the same temperature, so it doesn’t have units. Water is defined as 1.0, which means liquids with a specific gravity below 1.0 are lighter than water and tend to float, while those above 1.0 are heavier and tend to sink. This concept is about weight per volume relative to water, not color, viscosity, or vapor pressure, which is why the statement describing the liquid’s weight compared to water is the best choice.