calculate the amount of the major component in the eucalyptus oil and the amount of maleic anhydride you will need to use in the diels alder reaction.
JBE/KWK CHEM 222 Safety Issues Caution! Avoid contact with and do not breathe the dust of the maleic anhydride! use these reagents in a hood or under a fume extractor Procedure Spring 2018 away from flames and Analysis of Eucalyptus Oil by GC-MS-A sample 1 μãof the eucalyptus oil was injected into the GC- MS. Use the gas chromatograph and peak integration data provided on BlackBoard to calculate the percentage of all peaks produced from the eucalyptus oil. The sharp peak with a very low retention time is most likely acetone and not a component of the oil, and therefore was not integrated. Record the peak areas in your lab notebook and show your calculation for percent of the major component (largest peak area) in the oil Diels-Alder Reaction- Calculate the mass of the unknown CioHthe diene in 0.50 g eucalyptus oil ng the GC data (the percent composition of the largest peak of the eucalyptus oil) assuming that the peak areas are proportional to the component masses. The mass you calculate shoulc be entered into the synthesis data chart in your laboratory notebook. The diene and dienophile (maleic anhydride) are added to the reaction in equal molar quantities Calculate the moles of diene present in the 0.50 g eucalyptus oil and calculate the mass of maleic anhydride that you will add to the reaction All glassware must be clean and dry throughout the procedure as the maleic anhydride the Diels-Alder adduct are readily hydrolyzed by water and In a clean, dry microwave reaction vessel equipped with a stir bar dissolve 0.5 g eucalyptus oil in 5 mL THF and add the calculated mass of maleic anhydride. Cap the reaction vessel tightly and put into the microwave carrousel and record which slot your vessel is in. After the completion of the reaction using the microwave reactor let the vessel cool to room temperature. The actua measured mass of maleic anhydride should be entered into the synthesis data chart in your laboratory notebook. While your reaction is being heated, calculate the actual mass of the diene in your reaction based on the measured mass of oil in your flask and enter this value in the synthesis data chart and calculate the limiting reactant in your reaction If no crystals have formed by the time it is cooled to room temperature, create a nucleation site dipping a stirring rod into the solution, withdrawing it, allowing the ether to evaporate, then swirl the stirring rod in the solution. When the crystal formation appears to be complete, cool the flask in an ice water bath for an additional 5 minutes. Collect the product by vacuum filtration washing the crystals with 5 mL cold petroleum ether (place your flask with the petroleum ether in the ice water bath to cool while your crystals are forming) Recrystallize the Diels-Alder adduct from methanol in a small lask using a steam bath for a heat source. Just as the product can undergo hydrolysis with water, it can go through solvolysis with methanol. Avoid boiling the solution for extended periods of time. Once the product has been recrystallized and collected by vacuum filtration, transfer the crystals to a pre-weighed watch
12.) In the proton NMR of ethyl acetate, which group of hydrogens is the most magnetically shielded?
A.) A
B.) B
C.) C
13.) Rank the proton groups of the ethyl acetate molecule in order of increasing chemical shift.
A.) BAC B.) CAB C.) ACB D.) BCA
14.) Which of the following could happen when infrared radiation is absorbed by a molecule ?
Electrons are promoted from filled to empty molecular orbitals
The orientation of a nuclear spin state changes.
Intra-molecular bond angles change
molecule begins to rotate more rapidly
molecule may glow in the dark
15.) Infrared absorption spectra of organic molecules are often presented as a plot of transmittance versus wavenumber. What is the definition of a wavenumber ?
one wavenumber = one micron
one wavenumber = one centimeter
one wavenumber = one reciprocal micron
one wavenumber = one reciprocal centimeter
wavenumber is the same as wavelength, and can be expressed in any unit of length
16.) Which bond would you expect to have the highest vibrational frequency (stretching) ?
A) Urea
B) Sodium Carbonate
C) Potassium Iodide
D) Sulfuric Acid
E) Sodium Nitrite
Questions 17 through 20 are spectra identification problems. You must identify two unknowns, referred to as compound A and compound B. Table I, attached at the end of the exam, has a list of possible compounds. Each compound listed in table I has a two digit identification code. After you have identified compound A, you will enter the first digit of its identification code as the answer for question 18, and then enter the second digit of the code as the answer for question 19. You then repeat this process for compound B in questions 20 and 21.
17.) Compound A gives a positive acetyl chloride test, and the infrared and NMR spectra are given in figures 2A thru 2C. Consult table I and the spectra, identify compound A. The first digit of the code corresponding for compound A is
A) 1 B) 2 C) 3 D) 4 E) 5
18.) The second digit of the code for compound A is
A) 1 B) 2 C) 3 D) 4 E) 5
19.) You have run a series of qualitative chemical tests on compound B, all of which came out negative. The negative chemical tests included acetyl chloride, chromic acid, potassium permanganate, silver nitrate, and 2,4-dinitrophenylhydrazine. The infrared and NMR spectra of compound B are given in the attached figures 3A thru 3C. Identify compound B. The first digit of the code in table I corresponding to compound B is
A) 1 B) 2 C) 3 D) 4 E) 5
20.) The second digit of the code for compound B is
A) 1 B) 2 C) 3 D) 4 E) 5
21.) Which of the following statements regarding Grignard reagents is FALSE ?
A. The Grignard reagent is an example of an organometallic compound.
B. Grignard reagents are stable in anhydrous ether solutions.
C. A Grignard reagent contains electrophilic carbon.
D. Once prepared , a Grignard reagent should be used quickly.
E. Grignard reagents tend to act as Bronsted bases.
22.) Suppose that in the synthesis of benzoic acid , a student uses 1.215 grams of magnesium , 7.575 grams of bromobenzene , and 22.641 grams of dry ice. If the mass of benzoic acid obtained were 4.530, what was the percent yield?
