CHEM 14BL Chapter Notes - Chapter 2: Cuvette, Atomic Mass, Absorbance
25 Aug 2015
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Digital balance: 0. 2 mg = 0. 0002 g. *you will be using these absolute errors in your pre-labs and post-labs. Systematic error: examples in pipet lab: Random error: examples in pipet lab: Relationship between % rad and % inherent error. Purpose of calibration: to check experimenter"s precision/ accuracy of lab equipment. A comparison between % rad and % inherent error is used to check if the experiment was performed within the precision warranted by the equipment. Application of % rad and % inherent error. Example: using a 10-ml volumetric pipet, a student obtained the following amounts of water based on three trials: The absolute error associated with a 10-ml volumetric pipet is 0. 02 ml. Spectrophotometric analysis: measuring the concentration of solutes in solution by measuring the amount of light that is absorbed by the solution in a cuvette placed in the spectrophotometer. Assuming and l are fixed, beer"s law demonstrates that the absorbance is directly proportional to the concentration.
