Some Perspective on Quantitative Analysis Laboratory
General Laboratory Directions
The general purpose of this laboratory is to promote proficiency and familiarity with some common
techniques of chemical analysis, especially with their particular abilities and shortcomings.
problems and methods are those of classical wet chemistry, augmented with chromatography and
spectrophotometry, the approaches of equilibrium, kinetics, and stoichiometry are general for all
In lab, you will have "hands-on" experience with a number of specific analyses.
These have been selected with 3 goals in mind:
Workability – you should be able to succeed.
Utility – These are real
techniques that are frequently performed in working analytical laboratories,
for example, in clinical or police labs.
While you may never perform another titration after you
finish quant., you may well have occasion to submit samples for analysis.
The experience you gain
in this course should let you know what to expect from such an analysis - and what not to expect.
Representative – The 8 labs you will do are certainly not exhaustively representative of the
techniques of analytical chemistry.
However the concepts introduced, and the kind of thinking
required, are common to all analytical techniques. It will be necessary for you to consider what
interferes with a particular analysis, and what steps may be taken to avoid interferences.
For the last
lab, you'll even have the opportunity to design your own procedure.
The laboratory in conjunction with the lectures, should provide a good general feeling for the terms
"accuracy" and "precision."
It is important to know ahead of time what accuracy and precision are
needed for an analysis, and then select a technique (or devise one, if necessary) that is appropriate.
analyst's time in industry is charged out at something like $100 an hour (that's not the salary,
A company would quickly lose patience with an analyst or a researcher who does not
know, almost intuitively, how much analysis is needed, and what kind!
It is hoped that you will develop
some of that kind of intuition as you move through the course.
Because this kind of understanding is an important goal of this course, you should expect that it will
take more than extensive memorization to "ace" the course.
If you memorize formulas and procedures,
and do a respectable job in the lab, you will probably get by OK.
However, you will take little except
your grade with you when you finish.
On the other hand, if you put forth the little extra effort necessary
to understand the material, you will leave with a better idea of how to approach problems, not only of
analysis, but also of research in particular and life in general.
Besides, if you understand
you will find you need to memorize
The heart of quantitative technique is to carry a sample through one or more physical and chemical