[CHM 115] Lab

[Andrew J. Pounds]

On 09/17/13 14:05,  wrote:
> Hi Dr. Pounds,
>
>      To clarify on the report form for the lab, are we converting cm to nm and then to Energy for Hg Lamp and Sodium salt. Also can you explain the graph, it is a little confusing as to which variable is which, because the known would be nm wavelengths but it also wants the plot to be used to determine those same wavelengths?
>
> Thank you,
>
>

On the X-axis you should plot the position of your standards in nm from 
the Hg lamp:
violet    404 nm
blue      436 nm
green    546 nm
yellow    580 nm


on the y-axis is the actual position where you observed these lines on 
your spectrometer's
scale.   So you should have 3 or four points on your graph (depending on 
if you were able to record
the violet peak):

ordered pairs will then be...


(404, where you observed the line at 404)
(436, where you observed the line at 436)
(546, where you observed the line at 546)
(580, where you observed the line at 580)

These should form something that looks linear, so do a best fit line 
through the data points.  This will give you a function:

measured value = actual value * slope + y-intercept

Use this function to determine the actual values for all of your other 
readings.






-- 
Andrew J. Pounds, Ph.D.  (pounds_aj at mercer.edu)
Professor of Chemistry and Computer Science
Mercer University,  Macon, GA 31207   (478) 301-5627
http://faculty.mercer.edu/pounds_aj