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Q#
Question Text
4) Part I A. Preparing NaOH solution.
Scoring Scheme: 3321.
How many grams of pure, solid NaOH are required to make 1 Liter of 0.15M NaOH solution?
Express your answer to 2 significant figures, e.g. 3.3 g.
Mass (g) =
Your Answer:
6
You Scored
3
points out of
3
Possible
5) Part I A. Preparing NaOH solution.
Scoring Scheme: 3321.
How many grams of a solution that is 50% by weight NaOH is required to make 1 Liter of 0.15M NaOH
solution?
Express your answer to 2 significant figures, e.g. 6.6 g.
Mass (g) =
Your Answer:
12
You Scored
3
points out of
3
Possible
6) Part I A. Preparing NaOH solution.
Scoring Scheme: 3321.
The density of a 50% solution of NaOH is 1.525 g/mL. What volume of a solution that is 50% by weight
NaOH is required to make 1 Liter of 0.15M NaOH solution?
Express your answer to 2 significant figures, e.g. 6.6 mL.
Volume (mL) =
Your Answer:
7.90
You Scored
3
points out of
3
Possible
7) Part I B. Standardizing against KHP
Scoring Scheme: 3211.
Which of the following best explains why weighing by difference eliminates systematic balance errors?
Your Answer:
b. Because the mass is determined by the
difference between two readings, a systematic error in the
absolute mass on the balance will be removed by subtracting
the final weight from the initial weight.
You Scored
3
points out of
3
Possible
8) Part I B.
Data Entry  No Scoring.
For each of your THREE ACCEPTABLE trials (not the cursory one) in standardizing your NaOH against
KHP, enter the
mass in grams of KHP
for each of the three samples to one thousandth of a gram, e.g.
1.104g.
Your Answer:
1.19
No Points Possible
Your Answer:
1.0090
No Points Possible
Your Answer:
1.1570
No Points Possible
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View Full Document 9) Part I B.
Data Entry  No Scoring.
Please enter the volume in mL of NaOH required to reach the endpoint for each of the KHP samples and
enter the volume to a hundredth of a mL, e.g. 30.52 mL.
Make your volume entries in the order corresponding with the masses of KHP.
Your Answer:
38.99
No Points Possible
Your Answer:
34.80
No Points Possible
Your Answer:
39.98
No Points Possible
10) Part I B.
Scoring Scheme: 3321.
Please enter the values you calculated for each of your three trials for the molarity of your NaOH solution.
Place your molarity entries in the order corresponding with the masses of KHP and the volumes of NaOH
required for the trials. You should enter 4 significant figures, e.g. 0.1487 M .
Your Answer:
0.1494
You Scored
3
points out of
3
Possible
Your Answer:
0.1420
No Points Possible
Your Answer:
0.1417
No Points Possible
11) Part I B.
Scoring Scheme: 3321.
Please enter the value you calculated for the average of the three trials determining the molarity of your
NaOH solution.
You should report 4 significant figures, e.g. 0.1487 M
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This note was uploaded on 04/10/2010 for the course CHE 2a taught by Professor Tingguo during the Winter '08 term at UC Davis.
 Winter '08
 tingguo
 Chemistry

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