Gas Fitter Practice Test

What is the specific gravity of liquid propane compared to an equal volume of water?

1. 0.51

2. 0.60

3. 1.00

4. 1.52

The correct answer is: 0.51

The specific gravity of a substance is defined as the ratio of its density to the density of a reference substance; typically, water is used as the reference for liquids. For propane, its specific gravity is approximately 0.51 when compared to an equal volume of water. This means that for a given volume, propane is less dense than water. When we say the specific gravity of propane is 0.51, it indicates that a volume of propane weighs only 51% of the same volume of water. This property is significant in many applications, including fuel storage and transport, as it informs gas fitters about the behavior of propane in various environments, such as understanding its buoyancy and the way it may disperse or collect in different situations. The other options represent specific gravities which do not accurately reflect propane's characteristics compared to water. For example, a specific gravity of 1.00 would mean that the substance has the same density as water, while a value of 1.52 would indicate that it is much denser than water, which is inconsistent with the known properties of propane. Thus, recognizing the correct specific gravity of propane as 0.51 is vital for understanding its physical properties and handling requirements.