A 2.78 10^-4 M solution of a compound has an absorbance of 0.403 at 520 nm in a 1.00 cm cell. The solvent's absorbance under the same conditions is 0.020. Please see for assistance.

(a) What is the molar absorptivity of the unknown compound? M ^-1cm^-1 (b) What is the concentration of the compound in a solution, if the absorbance of the solution in a 1.00 cm cell at 520 nm is 0.327? M