Organic Chemistry
Predict whether the given molecule would absorb in the visible region or not.
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Identify the molecule that will most likely absorb light in the visible region.
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An unknown compound in a 3.0 x 10─4 M solution in hexane shows the absorption of 0.30 at 230 nm wavelength in a 1-cm cell. Calculate its molar absorptivity at this wavelength.
How can you distinguish between the following compounds using UV spectroscopy?
Arrange the given compounds from lowest to highest λmax.
Rank the following compounds from highest to lowest λmax.
Arrange the following compounds in decreasing order of λmax.
Which of the following is true when one of the ions in the given image is purple at pH 7; whereas the other is blue?
Compare the structure of cyclopent-1-en-2-one to the following compounds and predict its λmax.
Two different types of absorptions are observed in the UV spectrum of 3-methyl-1-phenylbut-2-en-1-ol: a weak absorption at 220 nm and a more intense absorption at 258 nm.When this compound is reacted with dilute sulfuric acid, an isomeric product with a weak absorption at 290 nm and a more intense absorption at 250 nm is obtained. Propose a plausible mechanism for the reaction described above. You should include the structure of the reaction product in your proposed mechanism.
Predict whether each structure shown below is likely to be colored organic compounds or not. Show the extended conjugation for structures that you predict to be colored by marking the series of continuous sp2 hybridized atoms.
A sample is prepared by dissolving 1.20 mg of a compound of molecular weight 180 in 10.0 mL of ethanol. The sample solution is poured into a 1.00-cm UV cell and the UV spectrum is taken. Determine the molar absorptivity of the sample if λmax = 250 nm, and the maximum absorbance at 250 nm is 0.630.
Determine the UV absorption maxima (λmax) for compounds (i), (ii), (iii), and (iv). λmax possible values are listed below.(a) 232 nm(b) 256 nm(c) 273 nm(d) 303 nm(e) 313 nm(f) 353 nm
