CHEM 222 HSTC Chemistry Diprotic Buffer System Components Questions

Exam 1 Fall 2022
Analytical Chemistry
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Exam 1 Fall 2022
Analytical Chemistry
Page 2 of 6
Name:_________________________
UIN: ________________________
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a.
Explain what is meant by diprotic acid and write two chemical equations for the H2CO3
buffer system that support your explanation.
b.
If the pH of a patient’s blood is measured to be 7.42 and the mEq/L of HCO3- is measured
to be 25, what is the concentration of all components of the diprotic buffer system described in
part a?
c.
Which of the following solution will best treat the patient and why? NaOH (0.1 M),
NaHCO3 (7.5 wt%), HCl (0.1 M), H2CO3 (1.96 g/L).
d.
If a pediatric patient has 2.7 L of blood at a pH of 7.28 and a HCO3- concentration of 19
mEq/L, how many mL of the solution proposed in part c are required to restore blood pH to
normal levels?
Exam 1 Fall 2022
Analytical Chemistry
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Name:_________________________
UIN: ________________________
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2.
a. What is the concentration of Pb2+ (Ksp = 3.0´10-44)?
b. Write balanced cumulative formation equations for each lead hydroxide species.
c. Calculate the concentration of each lead hydroxide species.
d. Calculate the total concentration of all lead species in the water. Is it above or below the US
EPA limit of 15 ppb? Explain your answer.
Exam 1 Fall 2022
Analytical Chemistry
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Name:_________________________
UIN: ________________________
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3.
a.
How many grams of Tris-HCl will you use?
b.
You have 1 M HCl and 1 M NaOH in lab, which will you use? Calculate the volume
used.
c. Show the reaction between Tris-HCl and the strong acid or base chosen in part b.
-Cl +H N
3
OH
d.
OH
OH
Prepare a brief procedure.
e. Complete the table below.
#
mL acid or base added
pH
A
B
C
0
4.090 mL 0.100 M HCl
5.00 mL 0.100 M NaOH
8.1
[Tris]
[Tris-HCl]
Ratio
[Tris]:[Tris-HCl]
Exam 1 Fall 2022
Analytical Chemistry
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Calculations for table in part e.
Part a
Part b
Part c
Exam 1 Fall 2022
Analytical Chemistry
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f. Complete the table below.
Molecular Picture
A
B
C
Relate picture to the calculation
pH Calculation (key steps)