Question

What is the concentration of copper sulfate in a 50 mL solution if the absorbance measured by a spectrophotometer is found to be 0.450 at a wavelength of 450 nm? The molar absorptivity of copper sulfate at this wavelength is 9.6 x 10^3 L/mol.cm.

Answer 1

To find the concentration of copper sulfate in the solution, 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 of the cuvette  in cm .In this case, we have:A = 0.450 = 9.6 x 10^3 L/mol.cml = 1 cm  assuming a standard cuvette We need to solve for c  the concentration of the solution :0.450 =  9.6 x 10^3 L/mol.cm  * c * 1 cmNow, we can isolate c:c = 0.450 /  9.6 x 10^3 L/mol.cm c  4.69 x 10^-5 mol/LSo, the concentration of copper sulfate in the 50 mL solution is approximately 4.69 x 10^-5 mol/L.