vitamin b12 is a protein with a cobalt ion coordinated at its center. you use a standard protein assay to quantify the concentration of the protein in an unknown sample containing the vitamin, and you believe its concentration to be 16 mm . to confirm the result, you denature the protein with heat and hcl (a strong acid), then isolate the salt solution that contains cocl2 . you intend to use spectroscopy to confirm the concentration of cobalt at a wavelength of 549 nm , but you suspect that the sample is too diluted to provide you an accurate value using a standard 1.00 cm cuvette. however, you notice that your spectrophotometer can accommodate larger sized vessels. use the ruler in the simulation to estimate the minimal path length you would require to obtain an absorbance measurement of at least 0.20 using a wavelength of 549 nm for a concentration of 16 mm (assuming the concentration you measured using the assay to be true)