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 22 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. Required:
Estimate the minimal path length you would require to obtain an absorbance measurement of at least 0.20 using a wavelength of 549 nm. Assume the concentration you measured using an alternative method (the assay) to be true.