CHEM 1411

February 4, 2015

Precision and Accuracy of Scientific Glassware

Pre-Lab Report

The objective of this experiment is to learn which scientific glassware should be used in various circumstances, how to measure volume and mass and how to record laboratory data and observations. Become familiar with significant figures, errors, precision and accuracy associated with the various tools and techniques. To Contain Glassware you will need two Erlenemeyer Flasks, one 125 mL to measure 100 mL and one 250 mL to measure 150 mL. You will also need one 100 mL beaker to measure 50 mL and two graduated cylinders, one 10 mL to measure 7.5 mL and one 25 mL to measure 22 mL. To Deliver Glassware you will need one 50 mL Burette to measure 35.00 mL. You will also need one 10 mL volumetric pipettes and one 10 mL measuring pipet to measure 7.5 mL.

First we will use the 125 mL Erlenemeyer Flask to measure 100 mL of solution. Before measuring, find the mass(g) of the empty flask and then fill the flask with 100mL of solution. Find the mass of the water by subtracting the mass of the flask with water by the mass of the empty flask, and find the volume of the water in the flask. Repeat these steps for three trials, and use the data collected to compute accuracy (absolute error and percent error) and precision (absolute deviation and percent deviation) at the end of the experiment for each set of measurements. Second we will use the 250 mL Erlenemeyer Flask to measure 150 mL of solution. First find the mass (g) of the empty flask and then fill the flask with 150 mL of solution. Find the mass of the water by subtracting the mass of the flask with water by the mass of the empty flask, and fins the volume of the water in the flask. Repeat these steps for three trials, and use the data collected to compute accuracy (absolute error and percent error) and precision (absolute deviation and percent deviation) at the end of the experiment for each set of measurements. Next we will use the 100 mL Beaker to measure 50 mL of solution. Before measuring, find the mass (g) of the empty flask and then fill the flask with 50mL of solution. Find the mass of the water by subtracting the mass of the flask with water by the mass of the empty flask, and find the volume of the water in the flask. Repeat these steps for three trials, and use the data collected to compute accuracy (absolute error and percent error) and precision (absolute deviation and percent deviation) at the end of the experiment for each set of measurements. Then we will use the 10 mL Graduated Cylinder to measure 7.5 mL of the solution. Next we will find the mass (g) of the empty flask and then fill the flask with 7.5 mL of solution. Find the mass of the water by subtracting the mass of the flask with water by the mass of the empty flask, and find the volume of the water in the flask. Repeat these steps for three trials, and use the data collected to compute accuracy (absolute error and percent error) and precision (absolute deviation and percent deviation) at the end of the experiment for each set of measurements. Next we will use the 25 mL Graduated Cylinder to measure 22 mL of solution. Before measuring, find the mass(g) of the empty flask and then fill the flask with 22 mL of solution. Find the mass of the water by subtracting the mass of the flask with water by the mass of the empty flask, and find the volume of the water in the flask. Repeat these steps for three trials, and use the data collected to