Packet 8: Bonus 13
This reaction mechanism occurs with an alkoxide ion and a primary alkyl halide in the Williamson ether synthesis. For 10 points each:
[10h] Identify this concerted reaction mechanism. A backside attack in this reaction mechanism results in a complete Walden inversion of stereochemistry.
ANSWER: SN2 [or bimolecular nucleophilic substitutions; prompt on SN or nucleophilic substitutions; reject “SN1” or “unimolecular nucleophilic substitutions”]
[10m] SN2 reactions are faster when performed with aprotic varieties of these molecules, such as acetonitrile or DMSO, since they shield the nucleophile less.
ANSWER: solvents [or aprotic solvents]
[10e] SN2 reaction rates also increase with the strength of the nucleophile, which is closely related to this property. Solutions with this property have a pH greater than 7.
ANSWER: basic [or alkaline; accept word forms like basicity or bases; accept word forms like alkali]
<Editors, Chemistry> | Packet H
| Editions | Heard | PPB | Easy % | Medium % | Hard % |
|---|---|---|---|---|---|
| 2 | 132 | 18.33 | 99% | 44% | 41% |
Conversion
| Team | Opponent | Part 1 | Part 2 | Part 3 | Total | Parts |
|---|---|---|---|---|---|---|
| McMaster A | Toronto A | 10 | 10 | 10 | 30 | HME |
| McMaster B | Guelph A | 0 | 0 | 10 | 10 | E |
| McMaster C | Queen's A | 10 | 0 | 10 | 20 | HE |
| Toronto D | Toronto B | 10 | 0 | 10 | 20 | HE |
| Toronto G | Waterloo C | 0 | 0 | 10 | 10 | E |
| Toronto H | Toronto F | 10 | 0 | 10 | 20 | HE |
| Toronto I | Brock A | 0 | 0 | 10 | 10 | E |
| Waterloo A | Toronto C | 10 | 0 | 10 | 20 | HE |
| Waterloo B | Toronto E | 10 | 10 | 10 | 30 | HME |
Summary
| Tournament | Edition | Exact Match? | Heard | PPB | Easy % | Medium % | Hard % |
|---|---|---|---|---|---|---|---|
| UK (North) | UK | Y | 5 | 22.00 | 100% | 60% | 60% |
| UK (South) | UK | Y | 8 | 18.75 | 88% | 63% | 38% |
| Northern California | US | Y | 4 | 25.00 | 100% | 75% | 75% |
| Southern California | US | Y | 7 | 21.43 | 100% | 57% | 57% |
| Eastern Canada (1) | US | Y | 5 | 24.00 | 100% | 80% | 60% |
| Eastern Canada (2) | US | Y | 9 | 18.89 | 100% | 22% | 67% |
| Florida | US | Y | 4 | 12.50 | 100% | 0% | 25% |
| Great Lakes | US | Y | 11 | 20.00 | 100% | 46% | 55% |
| Lower Mid-Atlantic | US | Y | 9 | 22.22 | 100% | 67% | 56% |
| Upper Mid-Atlantic | US | Y | 12 | 19.17 | 92% | 50% | 50% |
| Midwest | US | Y | 9 | 14.44 | 100% | 33% | 11% |
| North | US | Y | 4 | 15.00 | 100% | 25% | 25% |
| Northeast | US | Y | 12 | 16.67 | 100% | 33% | 33% |
| Pacific | US | Y | 8 | 22.50 | 100% | 63% | 63% |
| South Central | US | Y | 7 | 15.71 | 100% | 43% | 14% |
| Southeast | US | Y | 13 | 14.62 | 100% | 31% | 15% |
| Upstate NY | US | Y | 5 | 10.00 | 100% | 0% | 0% |