Question

What is the concentration of iron (II) ions in a given solution using spectrophotometry if the absorbance value obtained from a calibration curve is 0.58 and the molar absorptivity of iron (II) ions at the given wavelength is 9.6 x 10^3 L mol^-1 cm^-1?

Answer 1

To find the concentration of iron  II  ions in the solution, we can use the Beer-Lambert Law, which states:A =  * c * lwhere A is the absorbance,  is the molar absorptivity  L mol^-1 cm^-1 , c is the concentration  mol L^-1 , and l is the path length  cm .In this case, we have:A = 0.58 = 9.6 x 10^3 L mol^-1 cm^-1Assuming the path length  l  is the standard 1 cm, we can rearrange the equation to solve for the concentration  c :c = A /   * l c = 0.58 /  9.6 x 10^3 L mol^-1 cm^-1 * 1 cm c = 0.58 /  9.6 x 10^3 c  6.04 x 10^-5 mol L^-1So, the concentration of iron  II  ions in the solution is approximately 6.04 x 10^-5 mol L^-1.