2. Draw the structure for caffeine. What part of caffeine is basic?
PRE-LABORATORY EXERCISES NAME: Isolation of Caffeine Draw the structure of caffeine. what are the chemical and biological properties of caffeine? What are tannins? Draw some representative structures. How are tannins removed using sodium carbonate? What other phytochemicals are found in tea and coffee? 4. 109
1. What is an emulsion? How would an emulsion form during a liquid/liquid extraction? 2. Draw the structure for caffeine. What part of caffeine is basic? 3. What form is caffeine in when dissolved in soda? Draw the structure.
A Lewis structure of caffeine is given below. What parts of the structure of this molecule make caffeine basic? (Hint: what is missing from this diagram? ) H3C
Draw all the resonance structure of a caffeine
Consider the structure of caffeine (re-draw it here), and answer the following questions from a structural perspective. Caffeine is an alkaloid and, as such, is weakly basic. Circle and label the basic atom or atoms (hints: consider the base in Experiment 4C, and consult the Derivative procedure on page 235). Identify (circle on your structure) and discuss two different structural features that would account for solubility in methylene chloride (hint: think intermolecular forces). Identify (circle on your structure) and discuss...
1. Draw the chemical structure of caffeine, diclofenac, amitriptyline and papaverine. 2. Describe the mechanism of a mixed mode reversed phase and cation exchange SPE cartridge. 3. Describe the general layout of a UV/VIS spectrophometer.
a. Caffeine can be protonated under acidic conditions to form an imidazolium-like species. Draw the structure for this protonated form, then find and report a pKa value for the most acidic proton. b. Draw a reaction scheme between caffeine and water. Which side of the equilibrium is favored for this acid/base reaction? Hint: Use the pKa value from part a. c. Find and report a pKa value for phenol. Draw a reaction scheme between phenol and water. Which side of...
1. Draw the structure of caffeine indicating its molecular formula (CwHxNyOz) and molar mass. 2. On the average, people use one teaspoon (2.50 g) of instant tea to make an 8-oz glass of iced tea. The average glass of iced tea contains 10 mg of caffeine per oz. (a) Calculate the mass percent of caffeine in a glass of iced tea. 3. A student extracted 1.15 g of crude caffeine from 110.0 g of tea powder. After purification, he obtained...
Post lab Questions: 1. What is an emulsion? How would an emulsion form during a liquid/liquid extraction? 2. Draw the structure for caffeine. What part of caffeine is basic? 3. What form is caffeine in when dissolved in soda? Draw the structure.
What is the basic structural unit of silicate minerals? And draw the structure