Pre - solutions that one is using, for without this...

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Pre-Lab Jordan Wertheimer 1.In chemistry, what does the term "complex ion" mean? Give an example of a complex ion. A complex ion is an ion that contains a metal cation binded to one or more small molecules or ions (such as NH 3 , CN - or OH - ). The formation of a complex ion is a stepwise process and each step has its own characteristic equilibrium constant. 2. Select the value for EDTA concentration that you think you will need to make. Justify your choice. The concentration of EDTA titrant should be 0.1 M because with a low concentration of metal cations present in our water sample, you need a lower concentration of titrant. 3. Select the value for sample size for your sample that you think will be appropriate. I could choose to use 20 mL of water in our sample size to attain a final volume of around 10 mL of solution. Introduction: For this experiment, it is pertinent to note some background on the different
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Unformatted text preview: solutions that one is using, for without this previous knowledge, combinations of some of these chemicals could result in harm or injury. In the experiment, the main goal is to perform complexometric titration, in which a titration of solution occurs, but the end result is a formation of a complex ion, so that one can measure the concentration of a divalent metal ion in the solution that you have titrated. In our experiment, the given complexing agent is EDTA ( ethylenediaminetriacetic acid). 7. Draft a procedure for preparing your EDTA titrant. By knowing the molecular weight of the EDTA, you must measure a specific amount of the compound to make more than .5 L, in order to make a final solution of 0.1 M solution. Once these calculations are made, one can use the given amounts of EDTA to dissolve in 50 mL of water to begin titration into an Erlenmeyer Flask....
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This note was uploaded on 07/01/2009 for the course CHEM 152 taught by Professor Grall during the Spring '08 term at University of Arizona- Tucson.

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