s prepared and its absorbance was recorded with a 0.01 cm sample cell to give 0.88 % transmittance (T) at 400 nm. Calculate the concentration of each of the molecules given that the molar absorption coefficient of the thienothiophene is 23,000 L.mol-1cm-1 and the sexithiophene is 34,000 L.mol-1cm-1.

26. What exactly is flame atomic absorbtion spectrometer?

Consider ultraviolet radiation of wavelength 300 nm passing through 1.50 mm of a solution of absorbing substance at concentration 0.717 mmol dm-3. Transmission was found to be 61.5%. Calculate the molar absorption coefficient of the solute at 400 nm and express your answer in cm2 /mol.

The following data have been obtained in the calibration of a series of standards for the determination of iron, measuring the transmittance, at 506 nm and thickness of 1.00 cm of iron (II) solutions in which color with 1.10 has been developed -phenanthroline. [Fe] (ppm) 0.20 0.40 0.60 0.80 1.00 2.00 3.00 4.00 5.00 6.00 7.00 T (%) 90.0 82.5 76.0 69.5 63.5 41.0 26.3 17.0 10.9 7.0 4.5 Calculate the mean molar absorptivity of iron when determined by this method.

An absorbance calibration curve for Zn was fitted to equation A = 0.913×`Zn, ppm`.   Flask 1: To the first flask, a 1.00 mL aliquot of the unknown Zn solution was diluted to 100.0 mL in a volumetric flask; the absorption intensity from this sample was measured to be A = 0.204.   Flask 2: To a second flask, a 1.00 mL aliquot of the unknown Zn sample and a 1.00 mL aliquot of 10.00 ppm Zn solution were added and diluted to 100.0 mL in a volumetric flask; the absorbance of this sample was measured to be A = 0.294.   Calculate the % spike recovery for the analysis and report to the nearest whole number.   Hint: A=mC of the type y=mx, so C=A/m   %Spike=100%((Cspike-Coriginal)/Cadded))   Cadded can be found from C1 V1=Cadded V2.