Calculate the number of grams of this dye in the coating of one piece of candy?

Question

A yellow dye, FD&C yellow 3, is used in some candy coatings. A 0.000015 M solution of this dye has an absorbance of 0.209 at its (LANDA, max)
Calculate the number of grams of this dye in the coating of one piece of candy (M W of dye = 271 g/mole)

Answer 1

Not enough data here to solve. You need to provide a molar extinction coefficient, or the raw data fro a set of standards so we can use Beer’s Law to compute the molar extinction coefficient.

http://en.wikipedia.org/wiki/UV/Vis_spectroscopy

Also notice you did not provide any data about the single piece of candy, specifically how much volume was it dissolved in.

So for now the answer to your question is… You need more data.