Post Lab #1.docx - Post Lab#1 Volumetric Glassware...

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Post Lab #1: Volumetric Glassware CalibrationIntroduction:The goal of this lab was to familiarize ourselves with different equipment and materials that are going to be used throughout the course of this lab, specifically the analytical balance, thepipet and the buret. We also learned how to properly count significant figures to keep calculations as accurate as possible. Significant figures are important, especially when using analytical balances, because they are extremely sensitive. They are even sensitive enough to detect the mass of a single grain of any substance (Seely, 2016). This is also why it is important that the balance is tared before use and the balance must read “steady” before you are to place anything on the pan (Seely, 2016). Not only is it important to know how to take a measurement accurately, but it’s also important to know how to keep the number accurate when performing a calculation (Dartmouth College, 2014). This is done by reporting all calculations to the correct number of significant figures (Dartmouth College, 2014). When multiplying, or dividing, the final answer must have the same amount of significant figures as the least amount used during the calculations (Dartmouth College, 2014). When adding, or subtracting, the final answer must contain the least amount of decimal places used anywhere in the calculation (Dartmouth College,2014). It is also very important to note how to count significant figures and the fact that you are not to round any numbers throughout the calculation, only the final answer. Another thing that was practiced is learning when to round when performing mixed calculations. Many calculations were used as well, such as standard deviation and how to find the density of water at any given temperature. The final goals of this experiment were to understand what errors might occur in analytical chemistry experiments, how to solve or prevent them, and finally how to care for the glassware before the experiment beings and once the experiment was complete. For example, before the experiment begins, the volumetric pipet must be rinsed by inserting a few mL of water
into it and tilting it horizontally while rotating it. Errors are very important to note during labs, and it is especially crucial to learn how to detect or avoid them. Systematic errors, like an error inthe analytical balance, cannot be detected or reduced just by observing (Appalachian State University, 2017). However, a correction factor can be added to make up for any errors (Appalachian State University, 2017). On the other hand, random errors, whose causes are usually unknown, can be reduced by collecting plenty of data and averaging the number (Appalachian State University, 2017).Procedure and Materials:1.Analytical balance2.Coin 3.Tweezers 4.Kim wipe5.Weighing paper6.Calculator7.250 mL beaker8.Plastic container 9.25 mL volumetric pipet10. 150 mL beaker11. Pipet bulb12. 50 mL buret13. 100 mL volumetric flask14. Buret stand15. Stopcock16. ThermometerAnalytical Balance+ zero+ weigh weighing paper to 0.0001 g+ zero+ pick up coin with tweezer

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