Potassium ferricyanide has an extinction coefficient of 1020 1/M*cm at 420 nm. The absorbance of a sample of unknown concentration at 420 nm is 0.4268. If the path length is 10 mm, determine the concentration of the sample

Answer 1

Convert the path length to cm. Plug in Beer's law equation and solve for c.

A = ε l c

http://www.chm.davidson.edu/vce/spectrophotometry/beerslaw.html