This experiment was conducted to show how density is affected by mass and volume. Measurements of mass and volume were taken of two solids and two liquids, one known and one unknown for each. Their densities were calculated, using the formula: d = m/V (density = mass / volume) I..
Three metal cylinders were measured each for volume and mass in this experiment. One of the cylinders was aluminum, and the two others were unknown. The first measured sample was aluminum. A sample beaker was placed on a scale as a holder, then zeroed out. The aluminum was placed in the beaker, and the mass was recorded. A graduated cylinder was filled to the 15.00 mL mark with distilled water, and the aluminum cylinder was placed in it. The amount of displaced fluid was measured and recorded. The graduated cylinder was then emptied and then filled with 15.00 mL of tap water. The aluminum sample was placed in the graduated cylinder and the amount of displaced fluid was measured and recorded. The mass of aluminum was divided by each measurement of volume to find the density of the sample. This process was repeated with both unknown samples, unknown A and B.
From the densities and properties of the unknown metals, their identities were determined to be iron, for unknown A, and copper, for unknown B. The metal with the density closest to that of unknown A was iron. Unknown A has a density of 7.72 g/mL, and iron has a density of 7.87 g/mL III.. Unknown A also had the silver color of iron. Unknown B was determined to be copper because of its physical properties. The calculated density of unknown B would’ve suggested that it was nickel or cobalt, but the sample had a bronze color, which is a property of copper. These calculations matched closely to the accepted values of their respective metals, and the observed properties matched as well. Distilled and tap water both produced the same results when calculating density. Possible sources of error may have been from misreading the graduated cylinder, or inaccurate equipment.
The purpose of this experiment was to calculated the density of different metal samples from measurements of mass and volume, and to identify the unknown metals based on observations and numerical data. With an experimental error of 0.986 for aluminum, 1.91 for unknown A, and 0.781 for unknown B, it is concluded that this experimental process was valid and did not need to be drastically changed because the all percent errors were below 5 percent. The results of this lab provide irrefutable evidence that size does not matter. Although each sample had the same measured volume, unknown A and B could be considered more massive than the aluminum sample, in scientific terms, because they had more mass.