Number: 2006-010-1-500
Title: Adjustment, estimation and uses of equilibrium reaction
constants in aqueous solution
Task Group
Chairman: Igor V. Sukhno
Members: Vladimir
Y. Buzko and Leslie
D. Pettit
Objective:
To prepare (and improve) programs to treat quantitatively the dependence
of activity coefficients (and hence equilibrium constants) on ionic
strength and on the presence of dissolved gases.To explore and test
computer-based ways of displaying these effects graphically and the
influence they will have on species distribution curves.
Description:
A previous IUPAC project (# 2000-003-1-500)
has produced a suite of programs to study quantitatively the influence
of ionic strength changes on equilibrium constants, with particular
emphasis on using Specific Interaction Theory (SIT). In this project
we propose to extend this work in the following ways:
- To apply Pitzer parameters in a more general way to equilibria of
environmental and industrial importance. Particular importance will
be given to sea water and mixed fluids.
- To extend and improve a database of published SIT and Pitzer-related
parameters. This database may be accessed by all relevant programs
in the suite and may be edited by the user.
- Currently the package allows calculations on the effects of dissolved
O2. This will be extended to cover other environmentally important
gases (e.g. air, H2, N2, rare gases, N2O, CH4, and other paraffins
- To explore and test ways of displaying graphically the relationship
between ionic strength and temperature with activity coefficients,
lg Kº and lg K;
- To explore and test ways of displaying graphically the effects of
errors on the relationships studied above.
- To calculate, and demonstrate graphically, the effect of errors
on species distribution curves.
- To prepare a database of reliable literature values of the dependence
of stability constants on temperature.
> download the entire suite > aq_solutions.zip
(zip file - 6.52MB; update in April 2008) or access current version
from: public.kubsu.ru/aquasolsoft/
and select 'Projects'
Progress:
> July 2007 report update (pdf
file - 10KB)
> Feb 2008 progress:
- SIT and Pitzer-related parameters published between June 2006 and
January 2008 are being analyzed.
- A version of the SIT program to correct stability constants for changes
in seawater salinity and in electrolyte mixtures is being tested.
- A program to calculate the solubilities of N2 and rare
gases is being tested.
- A new version of project software is being released (Apr 2008):
> download the entire suite > aq_solutions.zip
(zip file - 6.52MB) or access version from: public.kubsu.ru/aquasolsoft/
and select 'Projects' or from Academic Software (www.acadsoft.co.uk)
Last Update: 30 April 2008
<project announcement published in
Chem. Int.
Sep-Oct 2006>