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### Topic: Beer's Law Plot  (Read 6337 times)

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#### ozzlomo

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##### Beer's Law Plot
« on: May 06, 2009, 01:36:43 PM »
If for example, on an exam, a teacher were to give students a Beer's law plot (graph), with absorbance on the y axis, and concentration in ppm on the x axis. The teacher gives the equation of the graph in the form y = mx + b, or y = .800x, for example. If the teacher asked for the absorbance, and gave the ppm value or the y-axis values, you would simply plug the values into the equation, and solve for y or x depending on what value he gave you, and that would be absorbance correct? If he asked for transmittance, then that would 10^-abs (ten to the negative absorbance). Please correct me if I am wrong.

#### ARGOS++

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##### Re: Beer's Law Plot
« Reply #1 on: May 06, 2009, 02:27:40 PM »
Dear ozzolomo;

All looks ok, except:
If the teacher asked for the absorbance, and gave the ppm value or the y-axis values, you would simply plug the values into the equation, and solve for y or x depending on what value he gave you, and that would be absorbance correct?
Correct:   . the x-axis values .   and:     . for y on x  ..

Good Luck!
ARGOS++
Formulas, in its best sense,  ARE ONLY Recipes for “A Picture”,  —
If you DON’T catch “The Picture”, you are lost, - for ever!      (A++)

There is ONLY one correct Formula for the “Hydrogen”:  —
The Atom/Molecule, ITSSELF!                          (Dr. R. Mory  1968)

"Make it AS SIMPLE AS possible,  — BUT NEVER SIMPLER!"  (A. Einstein)

#### ozzlomo

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##### Re: Beer's Law Plot
« Reply #2 on: May 06, 2009, 02:58:18 PM »
Or if he gave you the y-axis values, you would plug it into the equation, and solve for x. Right?

#### ARGOS++

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##### Re: Beer's Law Plot
« Reply #3 on: May 06, 2009, 03:02:19 PM »

Dear ozzolomo;

That’s right, but then you get not absorbance, then you solve for concentration.

Good Luck!
ARGOS++
Formulas, in its best sense,  ARE ONLY Recipes for “A Picture”,  —
If you DON’T catch “The Picture”, you are lost, - for ever!      (A++)

There is ONLY one correct Formula for the “Hydrogen”:  —
The Atom/Molecule, ITSSELF!                          (Dr. R. Mory  1968)

"Make it AS SIMPLE AS possible,  — BUT NEVER SIMPLER!"  (A. Einstein)