Post lab

Post lab - Post-Lab Data Summary Note : some questions will...

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Post-Lab Data Summary Note : some questions will display a variable like "nCount" or "SyInput" instead of an actual number in the data summary. Q# Question Text 3) Scoring Scheme: 3-3-2-1 When you use the half reaction method to balance the redox reaction between one mole of NBS and ascorbic acid to give L-dehydroascorbic acid and succinimide, how many moles of electrons are transferred? Number of Moles of electrons transferred = Your Answer: 2 You Scored 3 points out of 3 Possible 4) Scoring Scheme: 3-3-2-1 How many moles of NBS are consumed for every one mole of ascorbic acid reacted? Your Answer: 1 You Scored 3 points out of 3 Possible 5) Scoring Scheme: 3-3-2-1 In the presence of excess iodide ions, the iodine formed by reaction of iodide with NBS will react further to form triiodide ions. What does the triiodide combine with to form the blue color of the endpoint? Your Answer: c. Starch You Scored 3 points out of 3 Possible 6) Data Entry - No Scoring You were instructed to use approximately 100 mg of ascorbic acid to prepare your primary standard solution. Enter the precise mass in milligrams of the ascorbic acid used to prepare your primary standard solution: Your Answer: 130 No Points Possible 7) Scoring Scheme: 3-3-2-1 If one had weighed out precisely 100 mg of ascorbic acid for the primary standard solution and dissolved it in enough deionized water to make a 250 mL solution, the molarity of that solution would be 0.00227 M. Enter your calculated molarity of the ascorbic acid primary standard solution based on the precise number of milligrams of ascorbic acid you weighed out and entered above: Your Answer: 0.00295 You Scored 3 points out of 3 Possible 8) Data Entry - No Scoring In the standardization of the NBS solution, using the ascorbic acid primary standard solution, we must examine each of the three acceptable trials. Your titration volumes of the NBS solution should be approximately 20 - 30 mL.
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For each trial, enter the precise volume in mL of NBS solution used in the titration of your ascorbic acid solution (e.g. 20.34 mL): Your Answer: 30 No Points Possible Your Answer: 29.2 No Points Possible Your Answer: 29.8 No Points Possible 9) Scoring Scheme: 3-3-2-1 Using the volumes of NBS solution you just entered and the molarity of the ascorbic acid primary standard solution, calculate the molarity of the NBS secondary standard solution for each trial. Enter your calculated molarity of the NBS solution for each trial. Be sure to enter your calculated molarities in the corresponding order that you entered your NBS volumes previously. The NBS volume you entered for entry #1 previously should correspond to the NBS molarity that you enter for entry #1 here. Your Answer:
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This lab report was uploaded on 04/15/2008 for the course CHE 2C taught by Professor Enderle during the Spring '08 term at UC Davis.

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Post lab - Post-Lab Data Summary Note : some questions will...

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