How do I solve this, I’m lost !

Question

The molar absorptivity constant for ß–Carotene at its analytical wavelength is 139, 500M¯1cm¯1. Use beers law to protect absorbance of dilution D.

dilution D : 5.00 of dilution C(original volume), 10.00 mL (Final volume,mL) and the final concentration 2.00×10^-6 .

Answer 1

Beer's law states A = ecl

A = absorbance = ?

e = extinction = 139,500 M^-1cm^-1

c = concentration (M)

l = path length = 1 cm (assumed)

If the concentration of the solution being measured is 2.00x10-6 M (you didn't provide units), then we just plug this in to the Beer equation to solve for absorbance. The description you provide isn't exactly clear when you say dilution D: 5.00 of dilution C, 10.00 ml, etc. It doesn't make sense. But I'll assume the final concentration is as stated, and so we have the following:

A = (139,500 M-1cm-1)(2.00x10-6 M)(1 cm)

A = 0.279 units