Item 23: Question In its protonated form, bromothymol blue has a molar absorptivity of 13800 M¹cm¹ at 435 nm. At the same wavelength, the deprotonated form of bromothymol blue has a molar absorptivity of 3410 M¹ cm ¹¹. If a solution contains 2.80 x 105 M protonated bromothymol blue and 5.00 x 10 5 M deprotonated bromothymol blue, what is the absorbance of the solution in a 1.00-cm sample cell at 435 nm? 0.228 0.557 0.785 1.34

1. Consider the following absorbance spectra of two molecules. Which molecule electromagnetic absorbs higher energy radiation? Explain. Fig. A 0.8. 04 0.2 wavelength (nm] Fig. B 0. 0.4 100 200 30 400 500 v00 100 f00 wavelength [nm] Intensity

Analysis of Analgesics A TLC plate was developed with a series of anlagesics and the unknown sample. An image of the plate is shown below. The solvent can be seen as the gray portion of the plate. A scale and reference lines are drawn across the plate to make it easier to record the distance each compound traveled. Record your measurements to 1 decimal place. 6.0 cm 5.0 cm 4.0 cm 3.0 cm 2.0 cm 1.0 cm О сm 1 2 3 4 5 6 Enter the distance of the solvent (cm) (Round measurement to 1 decimal place) Table view List view Table 2. TLC Analysis Distance spot moved (cm) Rf value Spot #1: Aspirln Spot #2: Ibuprofen Spot #3: Acetaminophen Spot #4: Caffeline Spot #5: Naproxen Spot #6: Unknown

2. Calculate the absorbance value (A) for a solution that absorbs 89.5% of the light striking it. (Hint: What is the percent transmittance? Review the background reading)