Question

What is the concentration of copper ions present in a sample if the absorbance value is 0.345 and the path length is 1 cm? The molar absorptivity of copper ions is known to be 4.58 x 10^4 L mol^-1 cm^-1 at a wavelength of 600 nm in spectrophotometry.

Answer 1

To find the concentration of copper ions in the sample, we can use the Beer-Lambert Law, which states:A =  * c * lwhere A is the absorbance,  is the molar absorptivity, c is the concentration of the solution, and l is the path length.We are given the following values:A = 0.345 = 4.58 x 10^4 L mol^-1 cm^-1l = 1 cmWe need to solve for c  the concentration of copper ions . Rearranging the equation to solve for c, we get:c = A /   * l Now, plug in the given values:c = 0.345 /  4.58 x 10^4 L mol^-1 cm^-1 * 1 cm c = 0.345 / 4.58 x 10^4 L mol^-1c  7.54 x 10^-6 mol L^-1So, the concentration of copper ions in the sample is approximately 7.54 x 10^-6 mol L^-1.