vingar - Purpose: In this experiment the concentration of...

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Purpose: In this experiment the concentration of acetic acid in vinegar, bought from a grocery store, was determined by titration of the vinegar with a standard NaOH solution, a secondary standard. Oxalic acid was used for the standardization of the NaOH solution. Procedure: Titration: Standardization: The Oxalic acid standard was premade, 0.2500M using 3.200g oxalic acid. Important note Oxalic acid is corrosive use caution. Obtain one buret and rinse twice with 5ml of 0.5M NaOH. After buret was properly rinsed, fill buret above the 0.00ml mark, then drain to ~0.00ml, and record the initial volume. There should be no air left in the tip of the buret. Obtain a 250ml Erlenmeyer flask and carefully measure and record 10ml of oxalic acid. Add two drops of phenolphthalein. Begin titrating with NaOH this was done rapidly at first and mixing the solution by swirling the flask. When the end point approaches slow down the titration to drop-by-drop, swirling the flask well after the addition of each drop. The end point is reached when a faint pink color persists throughout the solution after it had been swirled this was an indication that the solution was basic. When the end point is reached, record the final volume. Repeat the titration with a second trial. Calculate the molarity of the NaOH solution from the two titrations. If the molarities agree within 1%, proceed to the next part. If they do not agree, do a third titration. It is important to note in calculating the molarity of the NaOH solution, there are
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This note was uploaded on 01/30/2012 for the course CHEMISTRY 212 taught by Professor Ha during the Spring '11 term at George Mason.

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vingar - Purpose: In this experiment the concentration of...

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