Chemistry Question?

Question

There are three parts to this question. 1. What is the meaning of the word "colorimetric"? 2. What must you vary in order to obtain a Beer's Law plot? and 3. To make a Beer's plot, what will u plot? Thanks for the help.

Answer 1

1. Colorimetric would be a measure of the intensity of a sample's color, as measured on a spectrographic instrument like a Spec20, which can be set at a particular wavelength. (Colorimetric anaylsis would be a measurement relating the solution's concentration or character to its absorbance at a particular wavelength or over a range of wavelengths).
2. My aging memory draws up the equation A =ebc (e stands for epsilon) for Beer's Law, which is absorbance =molar absorptivity e times path length b (length through which light must pass) times concentration c.
3. You can vary the concentration of a particular solution and measure the change in A (absorbance) . You would graph c on the x axis and A on the y axis. That way you can take any unknown concentration and determine it from where it falls on the standard curve you've drawn.