pH and Buffer Systems Lab Report
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rickypH and Buffer Systems Lab Report
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rickyCHEM 137.
1 – BIOCHEMISTRY (LABORATORY)
LABORATORY REPORT
Name ____________________________ Date Submitted: ____________
Lab Schedule: _____________________ Date Performed: ____________
Exercise No. 2
pH and Buffer System
I. OBJECTIVES:
II. RESULTS AND DISCUSSION:
A. Calibration of the pH meter
B. Factors Affecting Buffer Capacity
Effect of Concentration of Buffer
Phosphate Buffer
Concentration pH before NaOH was added pH after NaOH was added
Discussion: 0.005 M
0.05 M
0.10 M
Acetate Buffer
Concentration pH before NaOH was added pH after NaOH was added
Discussion: 0.005 M
0.05 M
0.10 M
Effect of the ratio of the conjugate base to weak acid
Phosphate Buffer
[Conjugate Base]
pH pH after NaOH was added
[Weak Acid]
6.2 -
7.2 -
8.2 -
Discussion:
Acetate Buffer
[Conjugate Base]
Discussion: pH pH after NaOH was added
[Weak Acid]
3.7 -
C.
4.7 -
5.7 -
Choosing the Proper Buffer Solution
1. Choosing the Proper Buffer Solution
In Protein Precipitation, two liters of 5mM buffer solution with pH 5.2 is needed in the
isolation of albumin. Which among the following buffer solution is best fitted for said
purpose? Justify your answer.
Buffer solutions pKa
Acetate buffer 4.73
Tris- (hydroxymethy) aminomethane 8.08
Phosphate buffer 7.20
Discussion:
2. Preparation of the Chosen Buffer System
Calculate and measure the amounts (in grams if solid and in mL if liquid) of weak acid
and conjugate base needed to be able to prepare the chosen buffer system in part A
above. Express your answer in useful units (that is, prepare it from practical amounts or
concentrations of starting materials).
D. Titration of an Amino acid
Graph:
Discussion:
E. pH of the Blood
III. CONCLUSION: