che 311 (311l) analytical chemistry (lab)sites.usm.edu/electrochem/analytical chemistry/lecture...
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Instructor: Dr. Wujian Miao
Lab Manager: Dr. Jian Sun
The University of Southern MississippiDepartment of Chemistry and Biochemistry
CHE 311 (311L)
Analytical Chemistry (Lab)
About this course
CHE 311-Analytical Chemistry Combined Syllabus can be downloaded from:
http://www.usm.edu/electrochem
Teaching 3. Spring, Summer and Fall Semesters Login Area
UserID “CHE311” and Password “Summer2008”
Few Tips For Success in the Class
• actively attending every class and take good notes
• improving your math (good math is absolutely essential)
• completing all homework and study textbook
• Taking CHE 311L VERY Seriously
• asking questions
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Final grade distribution of fall 2013
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10
20
30
40
50
A B C D F NA
Final No %A 1 3.03
B 7 21.21
C 13 39.39
D 7 21.21
F 4 12.12
NA 1 3.03
33 100
Final grade distribution of fall 2016Final No %
A 3 13
B 6 26
C 6 26
D 6 26
F 2 9
Total 23 1000
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10
15
20
25
30
A B C D F
Final grade distribution of spring 2017
Final No %A 1 7
B 4 29
C 7 50
D 2 14
F 0 0
Total 14 1000
10
20
30
40
50
60
A B C D F
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Survey and Q&A
Textbook for this course:
Fundamentals ofAnalytical Chemistry
(9th Ed, 2014)
Skoog-West-Holler-Crouch
Chapter 1
Introduction of
Analytical Chemistry
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What is Analytical Chemistry?
An unknown sample solution
The sample could contain:
(1) Ca2+, Na+, or K+ ions
OR(2) A urine sample from a
potentially pregnant woman
Your job:To tell what is the sample or is the woman pregnant?
Analytical Chemistry
What is the sample? How much is X in the sample?
Qualitative Analysis Quantitative Analysis
Ca2+Flame test
(Brick Red)
(EDTA titration)
Emission Spectroscopy (Spectroscope)
EDTA-CaComplex
Identification Quantitation
Hormone(protein)
Pregnancy Test Strip
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Analytical Chemistry
“The study of methods for determining thecomposition of substances.”
“The science of extraction, identification, andquantitation of an unknown sample.”
“What analytical chemists do!”
Two Areas:
Qualitative Analysis (what?) Quantitative Analysis (how much?)
Roles of Analytical Chemistry
• Forensics• Archaeology• Food• Pharmacy• Medicine
General Steps in a Chemical Analysis
From Greek“Food of gods”
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1. Formulating the Question
2. Selecting Analytical Procedures/Methods
1. What accuracy and precision are required?
2. How much sample is available?
3. What is the concentration range of the analyte?
4. What components of the sample will cause interference?
5. What are the physical and chemical properties of the sample matrix?
6. How many samples are to be analyzed?
Defining the problem:
Numerical Criteria for Selecting Analytical Methods
1. Precision
2. Accuracy
3. Bias
4. Sensitivity
5. Detection Limit
6. Concentration Range (Dynamic range)
7. Selectivity
Other Characteristics to Be Considered in Method of Choice
1. Speed (point of care diagnostic testing)
2. Ease and Convenience
3. Cost and availability of instrument
4. Per-sample cost
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3. Sampling
Aliquot—a portion of a larger whole, especially a
sample taken for chemical analysis or
other treatment.
Random Heterogeneous
Material
Segregated Heterogeneous
Material
4. Sample Preparation
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5. Analysis
6. Reporting and Interpretation
7. Drawing Conclusions
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The International System of Units (SI)
SI (International System of Units) Prefixes
Especially useful in this course
mega M 106
kilo k 103
centi c 10-2
milli m 10-3
micro 10-6
nano n 10-9
pico p 10-12
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Solution Terminology
• solute
• solvent
• aqueous solution
• liter
• atomic weight
• molecular weight (Formula Weight)
Molarity
# moles AMolarity => M = -------------------
# liters solutionor
# millimoles AMolarity => M = -------------------------
# milliliters solution
Useful Algebraic Relationships
wt A (g)# mol A = -----------------
fw A (g/mol)
# mol A = V (L) x M (mol A/L soln)
orwt A (mg)
# mmol A = -----------------fw A (g/mol)
# mmol A = V (mL) x M (mmol A/mL soln)
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Types of Solutions
• strong electrolyte
• weak electrolyte
• non-electrolyte
p-Functions
pX = - log10[X]
examples:
pH
pOH
pCl
pAg
Percent Composition
wt of a solutew - w% = -------------------- X 102 %
wt of solutionvol of a solute
v - v% = -------------------- X 102 %vol of solutionwt of a solute
w - v% = --------------------- X 102 %vol of solution
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Parts per Million (ppm)
wt of a solutecppm = ------------------- X 106
wt of solution
Remember:1 ppm = 1 μg (solute)/mL (solution) = 1 mg/LAssuming: solution density = 1.0 g/mL(it is true for most of the diluted aqueous solutions)
Practice: What is the molar concentration of 585 ppm NaCl? (10.0 mM)
Parts per Billion (ppb)
wt of a solutecppb = ------------------- X 109
wt of solution
Textbook Website:
http://www.thomsonedu.com/