Essay on Chem 2c Post Lab

1580 Words Apr 30th, 2013 7 Pages
Pos t-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
5) Data Entry - No Scoring
Enter the precise mass in GRAMS of the potassium iodate used to prepare your primary standard solution.
Your mass precision should be reported to a thousandth of a gram, i.e. 0.302. (Use 3 significant figures.)
Your Answer: 0.536
No Points Possible
6)

Scoring Scheme: 3-3-2-1
If one had weighed out precisely 0.500 g of KIO3 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 0.00935 M.
Enter your calculated molarity of the primary standard KIO3
…show more content…
You Scored 3 points out of 3 Possible
Your Answer: a. I2 (aq) + 2e - -> 2I-(aq)
15) Scoring Scheme: 3-2-1-1
Notice that the effective analytical connection for analysis of hypochlorite anion by the thiosulfate anion in this experiment is the sum of the two reactions:
1) hypochlorite anion with iodide anion to form iodine, and
2) thiosulfate anion with the iodine formed in reaction one.
In your laboratory notebook sum these two reactions to find the stoichiometric factor that relates moles of thiosulfate anion needed to react with each mole of hypochlorite anion in the bleach sample.
Then select the correct response.
Your Answer: b. Two mole s of thios ulfate anion ne e de d to re act with one mole of hypochlorite anion.

You Scored 3 points out of 3 Possible

16) Data Entry - No Scoring
For each of 3 acceptable trials, enter the mass of your bleach sample in GRAMS. Your mass precision should be reported to a thousandth of a gram.
No Points Possible

Your Answer: 1.05
Your Answer: 1.004
Your Answer: 1.02

No Points Possible
No Points Possible

17) Data Entry - No Scoring
For each of the 3 acceptable trials, enter the precise volume in milliliters of sodium thiosulfate solution used in the titration of your bleach samples (e.g. 20.34 mL).
Be sure to enter your trial volumes in the corresponding order that you entered your masses of your bleach samples previously.
The bleach sample mass you entered for entry #1 above

More about Essay on Chem 2c Post Lab

Open Document