Data has been collected to show that at a given wavelength in a 1 cm pathlength cell?

Question

Data has been collected to show that at a given wavelength in a 1 cm pathlength cell, Beer's Law for the absorbance of Co2+ is linear. If a 0.135 M solution of Co2+ has an absorbance of 0.350, what is the concentration of a solution with an absorbance of 0.360.

Answer 1

Use a simple proportion:

0.135 M / 0.350 = x M / 0.360

x = 0.139 M