can you help me with 5,6 and 8? thank you Acetone is a chromophore. It has a str
ID: 1026413 • Letter: C
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can you help me with 5,6 and 8? thank you
Acetone is a chromophore. It has a strong absorption peak at 195 nm and a weaker absorption peak at 274 nm. The two peaks are for different types of transitions. Explain why the peak at 195 nm has the strongest absorption 5. [ 3 marks ] 6. The gas phase spectrum and the liquid phase spectrum of the same chemical were obtained. Explain why the gas shows sharper peaks than the liquid phase. 1 3 marks ] 7. List three conditions that lead to a non-lincar situation for the relationship between absorption and centration of a sample. Ensure that your statements explain the condition(s) [3 marks ] 8. Consider the chemical structure of ethylene, 1,3-butadiene, 1,3,5-hexatriene, lycopene and beta- carotene. Predict the relative wavelength of maximum absorption ) for lycopene relative to 1,3,5- hexatriene. Explain your reasoning (be concise.) [3 marks ]Explanation / Answer
5. The chromophore in acetone is carbonyl group and it has got two types of transitions- n-* and - * and of these transitions - * is symmetry allowed and hence has strong absorption with higher max and appears at 195nm. n-*transition is a forbidden transition and appears at longer wavelength with an max of 10-15.
6. In the case of liquid phase sectrum of a chemical compound hydrogen bonding is possible and it leads to peak broadening . In gas phase spectrum hydrogen bonding is not possible as the molecules are far apart and so sharp peaks are observed.
7. three types of devaitons from are real deviations , chemical deviations and instrument deviations
Real deviations means deviation due to the limitations of BEER-LAMBERT law
chemical deviations due to the type and nature of analyte
8. 1,3,5 -hexatriene absorbs around 256nm whereas lycopene absorbs around 476 nm due the presence of conjugated double bonds . conjugation always leads to lower energy(longer wavelength) absorptions
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