Question

What absorbance value corresponds to 41.8% T? A = A 0.0110 M solution of a certain analyte exhibits 41.8% T at a wavelength of 280 nm. What will the percent transmittance be for a 0.0299 M solution of the same analyte? Assume the pathlengths for each measurement are equal. %T =

Answer 1

Part-A Calculating Absorbance: Transmittance = 41.80 % Absorbance = 2-log(Transmittance %) Absorbance = 2 -log( 41.80 ) Absorbance = 2 - 1.6212 Absorbance = 0.379 Part-B Calculating Absorbance: Absorbance = A path length = 1 Molar absortivity = e Concentration = C Beer's Law A = excx! Absorbance a Concentration A1 c1 A2 C2 here A1 = 0.379 (for 41.8%T) A2 = ? C1 = 0.0110 M C2 = 0.0299 M 0.379 A2 0.0110 0.0299 A2 = 1.030

Calculating Transmittance %: Absorbance = 1.030 Transmittance % = ? % Absorbance = 2-log(Transmittance %) 1.030 = 2-log(Transmittance %) log(Transmittance %) = 2 - 1.030 log(Transmittance %) = 0.970 Transmittance % = 100.97 Transmittance % = 9.339 Transmittance % = 9.339 %