Two objects can have the same weight but have densities that are completely different. Pure substances tend to have a constant composition but mixtures vary in amount with each part. This experiment is determining if each component in a mixture play a part in its density. By measuring the mass and volume of different pure substances and mixtures we can find the density of each. This process is done three times with different amounts in each. My lab partner and I calculated the density for water and isopropanol. We got around the same number each time. When conducting this experiment, there are a couple possible points of error. Isopropanol alcohol evaporates very quickly so the time it takes to make all the measurements, some alcohol could have been lost. Also, density depends on the temperature. In this experiment, the temperature was not controlled or specified. The amount of each individual component in a mixture has a direct variation with the overall density of the mixture. .
Materials and Methods.
This experiment consists of three parts (A, B, and C). For part A, start off by pouring about 20 mL of deionized water into the 50 mL beaker. Do the same with the isopropanol alcohol. These beakers are the sources for the pure liquids. It is important to not mix the two by using the same pipet. Put a dry beaker onto the top loader balancer and tear the scale. Make sure that this beaker is clean. Use a paper towel to dry it if the beaker is wet. Using a pipet, transfer a sample of water to the dry beaker you just scaled. Record how much water was transferred and record mass from the scale. Make sure to use the correct number of significant figures. Empty and repeat two more times. 2mL, 5mL, and 10mL are recommended but do not have to be exact. Use a different pipet and transfer a sample of isopropanol to a dry beaker. Make sure that the beaker is weighed and tore before transferring the sample. Record how much was transferred and the mass from the scale.