Exam 1 Questions on Organic Chemistry 1 with Solutions | CHEM 3311, Exams of Organic Chemistry

Download Exam 1 Questions on Organic Chemistry 1 with Solutions | CHEM 3311 and more Exams Organic Chemistry in PDF only on Docsity! Ce. 1, Write the letter that corresponds to the best answer for each question in the space provided (32 pts total). A la. Atropine is an example of an organic compound called an alkaloid. It is produced by the “deadly nightshade” plant and causes dilated pupils, impaired vision and other unpleasant physiological effects. Which functional groups are present in atropine? (4 pts) 2 aleohel OH 2 SAT . . YY a } avowehe ring Oo ANS ov Se NO atropine a) alcohol, amine, aromatic ring, ester b) alcohol, amine, aromatic ring, ether c) amide, ether, ketone, phenol d) amide, aromatic ring, carboxylic acid, phenol Cc 1b. What is the hybridization of the nitrogen alom.in atropine? (All atoms have zero formal charge, and lone pairs are not shown in the drawing.) (4 pls) a) sp b) sp? Cp sp" d) The nitrogen atom is not hybridized 8 Ic. What is the hybridization of the carbonyl oxygen in atropine? (4 pts) a sp ap sp 3 c sp da) The carbonyl oxygen atom is not hybridized D Id. According to valence bond theory, the bond between the oxygen atom and the hydrogen atom in atropine (note that there is only one O-H1 bond) is formed by the overlap of (4 pts): a) a“p” orbital on oxygen and an “s” orbital on hydrogen b) an “sp” orbital on oxygen and an “sp” orbital on hydrogen ¢ an “gph orbital on oxygen and an “s” orbital on hydrogen (@ an “gp? ” orbital on oxygen and an “s” orbital on hydrogen le. Label cach of the alcohols and amines shown below as primary (1°), secondary (2°), or tertiary (3°). (4 pts) dy OH ~ Y NH2 Cyr “NH ~ Oe ee ON 2° | o \ 0 2° if. For each. structure, label the indicated carbon atom (the one shown by the arrow) as primary (1°), secondary (2°), or tertiary (3°). (4 pts) 2 pe 2° 2° a ig. Calculate the formal charge on the indicated atom in each molecule. All lone pairs are shown. (8 pts) H us 0 Re 0H os oe Lass ) Hae "OH Ne \ -| oaen: 7 +1 Oxygen: Boron: Nitrogen: Carbon: {All hydragens are explicitly shown; show formal charge for the indicated C.) a 3. Draw an arrow-pushing mechanism lor the reaction of benzoic acid and water. Show all lone pairs, curved arrows and formal charges for full credit. Show the products of the reaction. Use the pk, of water and the other values given to determine which side of the reaction is favored at equilibrium. (15 pts) Potentially useful pK, values: oO cy ea Benzoic acid 4.2 Hydronium ion -1,7 benzoic acid Draw mechanism here: o Which side of the reaction is favored at equilibrium (circle it)? (Reactant) Products 4) Circle the correct answer to each question (18 pts). 4a) How many nodes are there in the Hz o* MO? Zero (One, 3 Twe 4b) How many nodes are there in a C=C x MO? Zero (One) Two 4c) Which is higher in cnorgy, a 1s orbital on H or an Hy ao MO? €) Eo Neither 4d) Acertain MO diagram has four bonding orbitals and four anti-bonding orbitals. How many atomic orbitals were mixed to produce this diagram? Four = ¢ Right? Millions The molecular orbital diagram for ammonia, NHa, is shown here. Although it is more complicated than the examples shown in class, the diagram is constructed in the same way, and the same concepts apply. MO diagram for ammonia, NH; a NI ota N-H cr (bonding MO) 4e) What is the HOMO in this diagram? Hs N sp? NHo { Non-bonding N-H o* 4f) What is the LUMO in this diagram? a Hs N sp* R-Ho Nun-bonding NA } oO gos creer benzoyl! peroxide (one pairs not shawn) 5) Benzoyl peroxide is a commonly used “free-radical initiator”, a chemical used to initiate a particular series of radical reactions, When heated to about 80 °C, the relatively weak O-O bond breaks homolytically and two identical radicals are produced. 5a) Draw a mechanism showing the process described above (the conversion of benzoyl peroxide to the two radicals). For full credit, show all curved arrows, lone pairs and unpaired electrons and any non-zero formal charges (5 pts). “95 OS AL. on ae —~> a Ws mu 10! gore. 5b) — Redraw one of the radicals produced in the reaction and draw an equivalent resonance contributor for it. For full credit, show ail lone pairs, unpaired electrons and any non-zero formal charges. Show the appropriate curved arrows to convert your original structure to the new resonance structure, Include the resonance atrow that shows the relationship of your two structures as resonance structures (4 pts) 10% 20% Cn eo ES