Abstract
Reactions catalyzed by hydronium ion or hydroxide ion (specific acid or specific base catalyzed reactions), when studied at controlled pH, can be described experimentally by pseudo-first-order rate constants that include the catalyst concentration or activity. Activation energies determined from Arrhenius plots using these pseudo-first-order rate constants will, in general, include contributions other than the intrinsic activation energy of the chemical reaction of interest. These extraneous contributions may include terms describing the dependence of activity coefficients on temperature, the variation of molar concentration with temperature, the heat of ionization of water, and the heat of ionization of a buffer acid. Quantitative expressions are derived for these effects, and experimental approaches are described that allow the intrinsic activation energy to be obtained.
- Received July 7, 1982.
- Accepted June 23, 1982.
- Copyright © Parenteral Drug Association. All rights reserved.
PDA members receive access to all articles published in the current year and previous volume year. Institutional subscribers received access to all content. Log in below to receive access to this article if you are either of these.
If you are neither or you are a PDA member trying to access an article outside of your membership license, then you must purchase access to this article (below). If you do not have a username or password for JPST, you will be required to create an account prior to purchasing.
Full issue PDFs are for PDA members only.
Note to pda.org users
The PDA and PDA bookstore websites (www.pda.org and www.pda.org/bookstore) are separate websites from the PDA JPST website. When you first join PDA, your initial UserID and Password are sent to HighWirePress to create your PDA JPST account. Subsequent UserrID and Password changes required at the PDA websites will not pass on to PDA JPST and vice versa. If you forget your PDA JPST UserID and/or Password, you can request help to retrieve UserID and reset Password below.