units for exp 17, s..f in logarithms, average deviation for "k"

[Robert Zellmer]

There are technically units for absorbance but you weren't told
what they actually are so don't worry about them in your tables.
However, even though [A] means molarity you need to still put
units in your headings.  They were not included for you in the
table in the manual.  Logarithms do not have units.

Also, often people don't handle sig. fig. properly for logarithms.
The s.f. in logs are to the right of the decimal point.  This is
discussed in the Appendix in the textbook.  I also discussed
this in lecture today and it's in my help file for exp 16. For
example, if you have a number with 4 s.f. and you take the log
(base 10 or natural log) your result should have 4 decimal
places.  It's the number of decimal places in the logarithm
which indicate the s.f. in the original number.

On the report sheet on page 45 for exp 17 you list the 4 rate constants
for the 4 solutions.  Then you are supposed to take an average and
calculate the average deviation.  Technically you should also check to
see if you should include all four rate constants in the average (i.e.
is one of them really different than the other three).  To do this you
should do an error analysis.

All of this is explained in the following link (which I sent previously
in an e-mail about exp 16),

*Treatment of Numerical Data (Error Analysis, sig. fig., graphing)* 
<http://chemistry.osu.edu/%7Erzellmer/chem1220/lab/App_D_122_lab_manual.pdf>

This link can be found at my "Laboratory" link.

Dr. Zellmer
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