Question
When an enolate ion is protonated, the predominance of one of these factors leads to enol formation, while the other leads to a ketone or aldehyde. For 10 points each:
[10h] Two answers required. Name these two factors that determine the composition of a reaction’s products. The deprotonation of an unsymmetrical ketone can form two different enolates by losing the more accessible proton or forming the more substituted double bond, depending on which of these factors predominates.
ANSWER: kinetic AND thermodynamic reaction control [accept in either order]
[10e] Pure thermodynamic control of a reaction is physically impossible since this state of the reaction is only reached after infinite time. This state occurs when the rates of the forward and backward reactions are equal.
ANSWER: dynamic equilibrium
[10m] Under pure thermodynamic control, after “infinite time”, the ratio of product concentrations becomes a function of this quantity and temperature. The natural logarithm of the equilibrium constant will equal negative this quantity over RT.
ANSWER: difference in Gibbs free energy [accept delta G or difference in G; prompt on Gibbs free energy or G alone by asking “what function of Gibbs free energy?”]
Summary
| 2023 UMN COOT | 08/19/2023 | Y | 3 | 16.67 | 100% | 33% | 33% |
Data
| BHSU | Jeff Weiner Fan Club | 0 | 10 | 0 | 10 |
| Palestrina Sawayama | Our Job is Buzz | 10 | 10 | 10 | 30 |
| doubleplusnegfive | Weird Klaus Barbie | 0 | 10 | 0 | 10 |