A 179 mL solution of a copper complex with a molecular weight of 491.9 g mol-1 was made. The absorbance of the solution at 638 nm wavelength was 0.376 using a 1 cm cuvette. It is known that this copper complex has a molar absorptivity (extinction coefficient) of 324.4 M-1 cm-1 at this wavelength.What was the mass of the copper complex dissolved in the solution in mg? Report your answer to 3 significant figures.

Question

A 179 mL solution of a copper complex with a molecular weight of  491.9 g mol-1 was made. The absorbance of the solution at 638 nm wavelength was 0.376 using a 1 cm cuvette. It is known that this copper complex has a molar absorptivity (extinction coefficient) of 324.4 M-1 cm-1 at this wavelength.What was the mass of the copper complex dissolved in the solution in mg? Report your answer to 3 significant figures.

DrBob222 · Answer

A = ebc A = 0.376 e = 324.4 b = 1 cm c = unknown. Solve for C in molarity. mols = M x L where L = 0.179\ grams = molos x molar mass. Solve for grams and convert to mg.

angela · Answer

is it 102 mg rounded to 3 significant figures.