Question
The linear relationship between these two quantities for closely-related reactions, such as similar solvents or substituents, may be a statistical artifact. For 10 points each:
[10h] Name both of these two quantities subject to a “compensation effect” that is a sufficient condition for LFERs (“L-F-E-R’s”).
ANSWER: entropy AND enthalpy [accept enthalpy–entropy compensation; accept S in place of “entropy”; accept H in place of “enthalpy”]
[10e] LFERs model linear relationships for this quantity, which is defined as the enthalpy of a system minus the product of temperature and entropy.
ANSWER: Gibbs free energy [or G; or Gibbs energy or reaction energy; prompt on free energy or potential energy]
[10m] This scientist’s namesake plot of “log K-sub-eq” against inverse temperature has enthalpy and entropy in the formulas for its intercept and slope, respectively. A quantity named for this scientist is less than one for compounds that dimerize in solution.
ANSWER: Jacobus Henricus van ’t Hoff (“van utt HOFF”) [accept van ’t Hoff equation or van ’t Hoff plot or van ’t Hoff factor]
<Harvard A, Chemistry>
Summary
| California | 2025-02-01 | Y | 3 | 10.00 | 100% | 0% | 0% |
| Florida | 2025-02-01 | Y | 2 | 10.00 | 50% | 50% | 0% |
| Great Lakes | 2025-02-01 | Y | 3 | 10.00 | 100% | 0% | 0% |
| North | 2025-02-01 | Y | 3 | 10.00 | 100% | 0% | 0% |
| Overflow | 2025-02-01 | Y | 5 | 14.00 | 100% | 40% | 0% |
| Pacific Northwest | 2025-02-01 | Y | 2 | 15.00 | 100% | 50% | 0% |
| South Central | 2025-02-01 | Y | 2 | 10.00 | 100% | 0% | 0% |
| Southeast | 2025-02-01 | Y | 3 | 10.00 | 67% | 33% | 0% |
| UK | 2025-02-01 | Y | 9 | 11.11 | 78% | 33% | 0% |
| Upper Mid-Atlantic | 2025-02-01 | Y | 6 | 8.33 | 67% | 17% | 0% |