What is the correct procedure to determine the density of a liquid?

To determine the density of a liquid accurately, the most reliable method involves measuring the mass of a known volume of that liquid, followed by calculating the density using the formula:

[

\text{Density} = \frac{\text{Mass}}{\text{Volume}}

]

This approach is fundamentally sound because density is defined as mass per unit volume, and obtaining both measurements allows for precise calculations. By measuring mass, typically using a balance, and volume, often using a graduated cylinder or volumetric flask, one can ensure that the density calculation reflects both the characteristics of the substance and the conditions under which the measurements are taken.

Methodologies such as using a hydrometer can also determine density, but they involve an indirect measurement and may not be as straightforward or accurate as directly measuring mass and volume. Similarly, multiplying volume by temperature does not yield density and is irrelevant to the calculation, while density calculations based on pressure and volume pertain to gases rather than liquids and do not directly relate to density determination in liquids.