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Topic: Spectrophotometry question  (Read 1063 times)

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Offline gotlembas

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Spectrophotometry question
« on: January 24, 2019, 03:45:03 PM »
Hi all, I'm having some trouble with a question for my organic chem pre-lab. We haven't gone over spectrophotometry at all in class and that's what our lab is on--all we have is a very short and not-very-informative lab manual to go on, so I turned to Google to try and find some answers but am still struggling. The question is as follows:

1. The %T vs wavelength graph of a certain solution has a maximum at 450 nm.
     a.What would be the color of this solution?
     b.In the absorbance vs. wavelength graph of the same solution, at which wavelength would you find the highest absorbance? Please explain briefly but clearly!

After looking at some graphs, my best guess is that the solution would be blue in color? I have no clue how to find the answer to the second part of the question. Any explanation would be much appreciated!

Offline Babcock_Hall

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Re: Spectrophotometry question
« Reply #1 on: January 24, 2019, 09:02:07 PM »
With respect to the second question, are you familiar with the equation that relates A to %T?

Offline wildfyr

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Re: Spectrophotometry question
« Reply #2 on: January 24, 2019, 09:47:06 PM »
If the %T is highest at 450 nm, that means what most of what color is being absorbed? If that's the case, which colors are not being absorbed? The combination of those colors is what color the solution would appear.

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