How do I Calculate the concentration of iron(lll) with absorbance measurement. Wavelength is 480nm, solution is 1 ml FeCl3 : 9ml HCl, absorption is .250A, concentration of stock FeCl3 solution is 0.00050M and stock HCl solution is 2.0M. I not sure how to use beer's law to find the concentration of the iron(lll) or is there a different equation I should be using?

Question

How do I Calculate the concentration of iron(lll)  with absorbance measurement. Wavelength is 480nm, solution is 1 ml FeCl3 : 9ml HCl, absorption is .250A, concentration of stock FeCl3 solution is 0.00050M and stock HCl solution is 2.0M. I not sure how to use beer's law to find the concentration of the iron(lll) or is there a different equation I should be using?

DrBob222 · Answer

Did you have a standard concn of Fe and you have an absorbance for that? Or do you the the absorptivity or extinction coefficient?

Hannah · Answer

No. I'm doing the questions in my lab manual and this is all the information I have. The lab is spectroscopic analysis of spinach. Test tube 1 has 9ml of 2.0M HCl and 1 ml of .00050M FeCl3 and 10ml of KSCN. But question asks for the concentration of iron lll before the KSCN is added. The KSCN is 100 ml of a 1.5M solution which had a mass weight if 14.578g. The mass of the spinach was 5.05g and the spinach extract was .413 absorption.

ben · Answer

did you manage to solve this?