Glassware Experiment

The primary goal of this experiment was to determine which types of glassware are the most accurate and precise in measuring substances. Another goal of this experiment was to help familiarize ourselves with the different types of glassware, and how we should handle the laboratory equipment. The accuracy and precision of a particular type of glassware is important because it allows for accurate measurements when performing different experiments. It also allows us to differentiate between glassware that is better for containing substances versus glassware that can deliver substances more accurately. In order to measure the accuracy and precision of the different types of glassware, we first chose seven different types of glassware. The general

After each group member performed 20 trials for each type of glassware, we were able to use percent error and standard deviation to determine which types of glassware are accurate and precise. In this experiment, it was important to measure the temperature of the water in order to record accurate densities, which can impact the mass of the water. After finishing the trials, our group subtracted the mass of the glassware without water from the mass of the glassware with water in order to find the mass of the water in grams. Then, we divided the mass of the water by the density(g/cm^3) of the water in order to find the volume (mL). An example calculation from the 5.00mL pipet is: (4.9285mL+4.8839mL+4.9367mL+4.9265mL+4.9134mL)/5 = 4.9178. In most cases, the temperature of the water was around 23 degrees celsius, making the density about .998408 g/cm^3 for many of the trials. The densities we used were found online. The next calculations we performed were to determine the average volume of the water in each person’s five trials by adding up all of the volumes(mL) and dividing that number by five. Using the average volume, we then calculated the

Then, we multiply the result by 100 to get a percentage number. An example calculation from the 5.00mL pipet is: ((5.00mL - 4.9178mL)/5.00mL)*100 = 1.6438%. The percent error allows us to see which type of glassware is the most accurate at measuring substances. From our results, we concluded that the variable auto pipettor was the most accurate, since it had the lowest percent error, at 0.0500%. The volumetric pipet, volumetric flask, and burette, all had similar percent errors at 1.0430%, 0.6394%, and 0.6619%, respectively. These results indicate that these glassware types are still very accurate. Next, the graduated cylinder had a percent error of 1.6400%, which is still relatively low, indicating that the graduated cylinder is also very accurate. The beaker and erlenmeyer flask both had higher percent errors, at 7.5218%, and 9.4146%, respectively. The beaker and the erlenmeyer flask were not accurate at measuring substances. This is perhaps because they are larger, and are meant to hold larger volumes of water, or they are meant to contain and pour substances. After finding out