Experimental Procedure
One of the key tasks in the context of laboratory research is to study the physical properties of the substances being worked on. Density is such a parameter of a substance that describes the content of grams of an object in a unit volume, for example, in liters. In other words, to calculate the density of a body, it is necessary to know the mass that this body has and the volume it occupies.
The present work focused on the purpose of measuring the density of objects in a laboratory room environment. Specifically, the objects given by the instructor were first examined visually, and then their mass was measured using scales. The volume of each object was measured by immersing it in a liquid (water) and measuring the difference between the water levels before and after the object was immersed. A 100 mL graduated cylinder, 25 mL graduated cylinder, 250 mL Erlenmeyer flask, and a 20 mL volumetric pipet were used to measure the volumes. The laboratory room temperature was 25.0°, which is a normal temperature that does not affect the volume changes of metallic bodies.
Observation
Three pieces of different shapes were used for the laboratory analysis: a metal beam, a metal cylinder, and a metal piece of non-constant shape. The nature of these metals was not postulated, but they all looked similar: they had a silvery luster and were quite heavy to the touch.
Results and Discussion
To calculate the density of each of the three objects, a single formula was used to relate body mass, volume, and, directly, density, namely:
ρ = m / V = m / ΔV
For object #1 (metal stick), the measured mass was 5.219 g. For object #2 (metal cylinder), the estimated mass was 8.388 g. Finally, for object #3 (metal of non-permanent shape), the estimated mass was equal to 6.224 g. In addition, the occupied volume for object #1 was 2.10 mL [72.10 – 70.00 mL], for object #2 was 3.00 mL [21.0 – 18.0 mL], and for object #3 was 2.30 mL [67.30 – 65.0 mL]. In other words, all the data for calculating the densities were ready:
ρ1 = m / ΔV = 5.219g / 2.10 mL = 2.49 g/mL
ρ2 = m / ΔV = 8.388 g / 3.00 mL = 2.80 g/mL
ρ3 = m / ΔV = 6.224 g / 2.33 mL = g/mL
Conclusion
The present laboratory work was aimed at studying the density parameter, which shows the ratio of an object to volume or the content of grams of a substance in a unit volume. On a practical level, the higher the density of a body, the heavier it is when it is equal in volume to a body with a lower density. In this paper, mass and volume measurements (via water displacement) were made for three metallic objects of different shapes. It was shown that the density of each was in the range of 2.49 to 2.80 g/mL. Indirectly, this result may indicate an aluminum origin for each of the three objects. However, the paper showed that even though all three figures are made of aluminum, their densities were not counted as identical.
A possible reason for this discrepancy could have been experimental errors. These include incorrect measurements of the mass of the object on the scales (incorrect reading or recording in the registration table) or errors in reading the volume of the body. In addition, it cannot be excluded that the objects were not made of pure aluminum and were, for example, alloys with different contents of aluminum and impurities, which led to differential results.