Final answer:
The graphical method for determining density is considered more reliable than mathematical methods because it integrates multiple measurements, reducing the impact of individual errors, and can reflect changes in density with varying conditions.
Step-by-step explanation:
The graphical method of determining density is often considered more reliable than the mathematical method for identifying unknown substances because it minimizes potentially compounding errors that can occur during calculation. When computing density mathematically, you separate the mass and volume measurements and then divide them. However, this approach can be prone to errors if measurements are not precise or if errors in dimensional analysis occur.
The graphical method also works well when dealing with substances for which density is known to vary with changes in environmental conditions, such as temperature and pressure. By plotting density against these variables, you can obtain a more nuanced understanding of the substance's characteristics.
In summary, the reliability of the graphical method rests on its ability to integrate multiple measurements and reduce the effect of individual measurement errors, as well as its capacity to provide insights into how density changes with varying conditions.