04-BS-12 · May 2018
Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)
National Exam 04-BS-12, Organic Chemistry — May 2018. 3 hours, closed-book examination (one Casio/Sharp-approved calculator and one hand-written aid sheet permitted); NOTES on page 1 state that TEN (10) questions constitute a complete exam paper and only the first 10 as they appear in the answer book are marked, but this sitting prints 13 numbered questions — every question and sub-part below is answered in full.
Reference texts: McMurry, Organic Chemistry, 9th ed. (drug acid–base/salt pharmacokinetics, steroid/bile-acid amphiphilicity, arene-oxide metabolism, cyclopropane stereochemistry and CIP assignment, reaction-energy diagrams, ester equilibria and intramolecular effective molarity, SN2 stereochemistry at a common stereocentre, named-drug synthesis design, epoxide ring-opening stereochemistry, mass-spectral formula discrimination, opioid IR/NMR structure elucidation, keto–enol tautomerism and conjugation/acidity, and condensation-polymer monomer identification). Every molecular formula, mass-balance, exact-mass, and stereochemical (R/S) assignment below.
Question text not reproduced: the examination questions are © Engineers and Geoscientists BC. Open the official past paper (linked at the top of this page) to read the question, then follow the worked solution below.
Both Teflon and poly(ethyl acrylate) are simple addition (chain-growth) polymers: the repeat unit shown in the backbone is exactly the monomer's own atoms with the C=C π-bond opened into two new C–C σ-bonds to neighbouring repeat units, so the monomer is found by literally reading the repeat unit back as a discrete alkene (no atoms are gained or lost, unlike a condensation polymer). For Teflon, –(CF2–CF2)n– comes from tetrafluoroethylene. For poly(ethyl acrylate), –(CH(COOEt)–CH2)n– comes from ethyl acrylate.
For poly(methyl methacrylate), each monomer's own C=C simply becomes the new backbone C–C bond; the ester side chain (–COOCH3) and the extra methyl on the former alkene carbon are carried along unchanged:
