Theoretical Calculations of Acid Dissociation Constants: A Review Article

Acid dissociation constants, or pKa values, are essential for understanding many fundamental reactions in chemistry. These values reveal the deprotonation state of a molecule in a particular solvent. There is great interest in using theoretical methods to calculate the pKa values for many different types of molecules. These include molecules that have not been synthesized, those for which experimental pKa determinations are difficult, and for larger molecules where the local environment changes the usual pKa values, such as for certain amino acids that are part of a larger polypeptide chain. Chemical accuracy in pKa calculations is difficult to achieve, because an error of 1.36 kcal/mol in the change of free energy for deprotonation in solvent results in an error of 1 pKa unit. In this review the most valuable methods for determining accurate pKa values in aqueous solution are presented for educators interested in explaining or using these methods for their students.

What Ended the Great Depression? Re-Evaluating the Role of Fiscal Policy

Conventional wisdom contends that fiscal policy was of secondary importance for the economic recovery in the 1930s. The recovery is then connected to monetary policy that allowed non-sterilised gold inflows to increase the money supply. Often this is shown by measuring the fiscal multipliers and demonstrating that they were relatively small. This paper shows that problems with the conventional measures of fiscal multipliers in the 1930s may have created an incorrect consensus on the irrelevance of fiscal policy. The rehabilitation of fiscal policy is seen as a necessary step in the reinterpretation of the positive role of New Deal policies for the recovery.