Yoon, Seong Meen – Homework 7 – Due: Oct 29 2007, 11:00 pm – Inst: James Holcombe
1
This
printout
should
have
24
questions.
Multiplechoice questions may continue on
the next column or page – fnd all choices
beFore answering.
The due time is Central
time.
001
(part 1 oF 1) 10 points
The curve For the titration oF hypochlorous
acid (HOCl) with NaOH(aq) base is given
below.
0
2
4
6
8
10
12
14
0
20
40
60
80
100 120 140
Volume oF base (mL)
pH
Estimate the p
K
a
oF hypochlorous acid.
C
a
= 0
.
75,
C
b
= 0
.
5775, and the volume
oF HOCl is 100 mL.
1.
77
2.
38
.
5
3.
None oF these
4.
10
.
2
5.
7
.
5
002
(part 1 oF 1) 10 points
It required 25.0 mL oF 0.333 M NaOH solution
to completely neutralize 15.0 mL oF H
2
SO
4
so
lution. What was the molarity oF the H
2
SO
4
?
1.
0.555 M
2.
0.200 M
3.
1.11 M
4.
0.278 M
003
(part 1 oF 3) 10 points
Below is the pH curve oF a weak acid (HA)
titrated with strong base.
Answer the Fol
lowing question based on the interpretation
oF this pH curve. Be as accurate as possible.
0
5 10 15 20 25 30 35 40 45 50 55 60
0
1
2
3
4
5
6
7
8
9
10
11
12
13
Titration Curve
Amount oF
Base
added (mL)
pH
What is the pH at the equivalence point oF
this titration? Answer in units oF pH. Your
answer must be within
±
10%.
004
(part 2 oF 3) 10 points
How much base much be added to make the
solution equalized? Answer in units oF
mL.
Your answer must be within
±
10%.
005
(part 3 oF 3) 10 points
What is the p
K
a
For this acid? Your answer
must be within
±
5%.
006
(part 1 oF 1) 10 points
A
student
titrated
a
sample
containing
106 mL oF 0
.
3 M NaOH with 0
.
7 M HCl.
What is the pH oF the solution aFter 21 mL oF
the hydrochloric acid has been added?
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View Full DocumentYoon, Seong Meen – Homework 7 – Due: Oct 29 2007, 11:00 pm – Inst: James Holcombe
2
1.
7
2.
0
.
86
3.
13
.
14
4.
14
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 Spring '09
 Hackert
 pH, ml, Seong Meen

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