Based on structure (Figure1), rank them in terms of increasing polarity for the
ID: 519043 • Letter: B
Question
Based on structure (Figure1), rank them in terms of increasing polarity for the organic compounds beta-carotene, Alizarin Red (1, 2-dihydroxyanthraqsulfonate), and Thymol Blue (note isopropyl groups). Explain your reasoning based on structure. Calculate the polarity P' values for 2:1 hexane: isopropanol and compare to 100% methanol. Calculate the polarity P' values for 3:1 water-methanol and compare to 100% isopropanol. Obtain a test tube rack with two sets of 8 clean dry test tubes. Label each set of tubes with numbers from 1 to 8. The first set will be used for the first eluent (solvent or in the experiment. When you change eluents, begin using the second set of tubes. During elution you will collect 20 of eluate in tube in number order. You will determine which analyte is eluting first or second b visual inspection of the eluate before and after adding dilute NaOH.Explanation / Answer
1. beta carotene :
2. Alizarine red :
3. Thymol Blue:
Thymol blue is more polar than Alizarine red which is more polar than beta carotene. Beta carotene has a conjugated system of electron where the electrons are deolcalized in the molecule and thus having no. net dipole moment. In Alizarine red OH and SO3Na participates in Hydrogen bonding that is intramolecular hydrogen bonding therefore the electron on O in OH group will be delocalized. The keto group cancel each other polarity. Therefore only OH group present at 1st position will only contribute to polarity.
In Thymol BLue net polarity is due to presence of OH group, SO3H group and keto group.
4. Calculate polarity of 2:1 hexane:isoprapranol :
polarity of hexane = 0.009
polarity of isopropranol = 0.546
2:1 hexane:isoprapranol: Hexane= 66 mL, water= 33mL
66*0.009 + 33*0.546 = 18.612
100% methanol = 100 mL
polarity of methanol : 100*0.762 =7.62
polarity of 2:1 hexane:isopropranol is greater than 100% methanol
5. 3:1 water:methanol ;
polarity of water: 1
polarity of methanol: 0.762
3:1 water:methanol, water= 75 mL, methanol= 25 mL
75*1 + 25*0.762 = 94.05
100% isopropranol = 100 mL
polarity of isopropranol = 0.546
polarity = 100 *0.546 = 54.6 mL
polarity of 3:1 water:methano is greater than 100% isopropranol
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.