Software for the quantitative treatment of equilibria in solution |
Aq_Solutions is a suite of programs for all scientists interested in the quantitative treatment of equilibria in solution. These will be important tools for all scientists working in environmental, medical, industrial and educational fields. They have been developed with help and encouragement from the Analytical Division of IUPAC.
The suite consists of a controlling program (Aq_Solutions.exe). This gives access to a suite of programs which, it is planned, will be regularly extended and up-dated. The principle authors are Igor V. Sukhno,Vladimir Y. Buzko (Krasnodar, Russia) and Leslie D.Pettit, Academic Software, UK (e-mail: pettit@acadsoft.co.uk).
Programs include:
SIT |
To correct stability constants
for changes in ionic strength using SIT (Specific Interaction Theory) and
to estimate SIT parameters with full statistics. It contains an editable
database of published SIT parameters. It also provides routines to inter-convert
MolaRities (c) and MolaLities (m), and lg K(c) and
lg K(m). A version of the SIT program to correct stability constants for changes in seawater salinity and in electrolyte mixtures (fluids) is in preparation. |
Electrolytes |
To calculate electrolyte activity
coefficients, osmotic coefficients and the activity of water using Pitzer
and the Lin-Tseng-Lee equations. Also to calculate ionic activity coefficients using the Millero-Pitzer method. A version of the Electrolytes program to calculate the ionic activity coefficients for the most important ions in seawater is in preparation. |
Acid-base |
Acid-base: To calculate the
composition of acid-base systems at equilibrium in electrolyte solutions
and seawater. To also calculate H+ activity coefficients for correction
of paH to p[H+] in different ionic media. The concept of apparent equilbrium constant is used to calculate equilibrium constants for more than 260 mono and polycarboxylic acids with background ions. A version of the Acid-base program to calculate the H+ activity coefficient in seawater at different salinity (chlorinity) and at different temperature is in preparation. |
Temperature effects |
Temperature effects: To study
and predict the temperature dependence of lg K using eight thermodynamic
equations: Van't Hoff equation Isobar equation Extended Isobar equation Clarke-Glew equation Extended Clarke-Grew equation DQUANT equation Valentiner equation Blandamer-Robertson-Scott equation Full statistics are included. |
Gas
solubility |
To calculate O2
solubility in water, 22 electrolyte solutions, natural fluids and seawater
as a function of temperature, concentration and salinity. A program to calculate the solubilities of other gasses is in preparation. |
Speciation |
To calculate & display species
distribution curves for complexes (including insoluble species). Speciation
may be displayed as a function of pH, pL (any reactant) or total reactant
concentration and as either percentages or as species concentrations (log
values). When insoluble phases are present lg S values may also be plotted.
Both graphs and tables of numeric values may be displayed, printed or saved
to disk. The sensitivity of speciation curves to errors in lg K values may be demonstrated graphically. |
Titration
simulations |
To simulate M-L titration curves in real time and display speciation dynamically. Species L, HL, H2L, ML, ML2, MHL and MH-1L may be included and stability constants adjusted in real time. Titration curves, speciation curves and pi-charts are calculated in real time. |
In addition, other programs are in
preparation. and will be included at a later date.
These include programs for electrode calibration, for properties of individual
electrolyte solutions and their mixtures (solubility, density, viscosity, DCp,
freezing-point, boiling-point, surface tension), for water properties as a function
of temperature, pressure and concentration of individual electrolytes or electrolyte
mixtures (aw, pKw, DHw, DCp, viscosity, density).
Download Aq_solutions
as a .zip file (7 MB). Unpack, retaining the directory structure.