Specific gravity of a liquid is determined by its:

Specific gravity is a dimensionless quantity that represents the ratio of the density of a substance to the density of a reference substance, which is typically water for liquids. When determining the specific gravity of a liquid, it is essential to compare its weight (or more accurately, its density) to that of water because water is a common reference point that is easily accessible and is used extensively in various scientific and engineering calculations.

The specific gravity is calculated using the formula:

Specific Gravity = (Density of the liquid) / (Density of water)

Water has a density of approximately 1 g/cm³ at 4 degrees Celsius, which makes it a useful standard for various liquids. If the density of the liquid is greater than that of water, it will have a specific gravity greater than 1, indicating that it is denser than water. Conversely, if the density is less than that of water, the specific gravity will be less than 1, indicating that it is lighter than water.

Using water as a reference allows for easy comparison since it is commonly understood and its properties are well-documented, making it the preferred choice for determining the specific gravity of liquid substances.