This set of laboratory experiments is designed to introduce you to some of the apparatus and operations you will be using during the remainder of this course, including the treatment of data using spreadsheets. While some of the procedures may seem trivial and the results obvious, this is a chance for you to develop good laboratory technique.
Required Reading
D.C. Harris, Quantitative Chemical Analysis (8th ed., W. H. Freeman, NY, 2010) chapter 2 (Tools of the trade) Electronic Balances (including Weighing by Difference), Analytical Lab Manual.
Burettes, Analytical Lab Manual.
REAGENTS AND APPARATUS
• Analytical Balance
• 400 mL beaker
• 3 - 2 oz. plastic bottles with caps
• 5 mL volumetric pipet
• 100 μL Eppendorf micropipet
• thermometer
• distilled, deionized water
• 2 , 50 mL burets
PART A - USE OF THE ANALYTICAL BALANCE
The analytical balances in the lab are probably the most precise, accurate and reliable pieces of equipment that you will use during the semester. To understand how these balances operate and their limitations you should read the appropriate section in your textbook. Although there are inherent limits in the accuracy and precision of these balances most weighing errors are caused by incorrect handling of the sample. In the first part of this lab you will investigate several potential sources of error.
PROCEDURE
1. In this section you will determine the mass of a clean, dry weighing bottle under various conditions. Unless instructed otherwise, you should handle the bottle with your crucible tongs, gloves, or lint-free paper and measurements should be made to the nearest 0.1 mg.
Begin by placing the weighing bottle and cap (with cap removed) in the oven for about 5 minutes. Remove and re-mass while warm. Follow the change in its apparent mass for several minutes, reweighing every thirty seconds. Record all masses including the final
constant