CerkoLab-EQSOL program, varying on version, allows modelling of the equilibria points in solutions. It is possible to simulate potentiometric titration curve, to determine constant equilibria, stoichiometry, titrand’s ingredients concentration, electrode parameters, ionic strength and activity coefficient for the systems of any degree of complexity.

Functioning of the program is based on the model of symbolic equations depicting particular equilibria.

Owing to the adjustment of the calculated titrant curves to the experimental curves, by the use of nonlinear method of the least squares, the program generates theoretical titration curve and estimates all quantities describing the model, including the type of solution: ideal, Debye-Hueckel or Davies.

Additional tools allow further specific analysis of acquired data. Simulation Function can be particularly useful in didactics to generate titrants’ curves of any systems.

Supplementary informational materials:


Routine procedures and analytical tools


Chlorides contentplik PDF
Fluorides contentplik PDF
Fruit acidsplik PDF
Peeling acid valueplik PDF
Carbonates contentplik PDF
Lincomycin contentplik PDF
Titrantplik PDF
pKa monoprotic acidsplik PDF


Microburette/Micropumpplik PDF
pH regulatorplik PDF
Determination of liquid density

Determination of solubility
Limiting conductivityplik PDF
Spectrophotometric spectra analysisplik PDF

Types of measurements

Measurement sensors calibration
Auto-pause titrationplik PDF
Double titrationplik PDF
Titration with molar concentration constant step
Programmed titrationplik PDF

Determination of constant equilibria of chemical reactions using potentiometric methods

Determination and modelling of pKi values

Adjustment pKi tool allows the adjustment of pKi values based on titration curves in electrolytic systems by means of algorithm „cvequid” elaborated by J. Kostrowicki and A. Liwo. The used algorithm allows the determination of constant equilibria (pKi) of chemical reactions in electrolytes mixtures of any degree of complexity. Calculation procedures are performed on the basis of symbolically written model equilibria, for example:

H2L=H+HL diprotic acid, first degree of dissociation, pK1 sought
HL=H+L second degree of dissociation, pK2 sought
0=H+OH water solvent, pKw sought

and automatically generated stoichiometric matrix being the starting point for calculation.
As a result of iterative procedures, the following information is obtained: modelled concentrations, the capacities of ingredients and data concerning electrode characteristics with the full statistics. The result is shown in the form of tabular notes and modelled titration curve on the basis of measuring points.

Determination of pKi in binary-solvent systems

Cerko Lab System pK binary systems program is intended for determination of pKA, pKB values of weak acids (HL) in clear solvents A and B as well as relations pK with mole fraction and solvent B in the mixture of A+ B solvents.
Determination of pK(x) function in total scope (0≤x≤1) of molar index (x) changes in the mixture of A+B solvents requires two mutual titrations, where the HL/A+B system is obtained by titration of HL/A solvent with HL/B solvent and HL/B solvent with HL/A. The obtained data allow the determination of pK(x) values on the basis of modified Redlich-Kister, Myers-Scott and/or Tadeusz Michałowski’s model.

Determinatiom of pKa monoprotic acids

pKa module allows quick determination of monoprotic acids’ pKa values on the basis of single titration curve.

Supplementary informational materials:

pKi values modellingplik PDF
pK of binary systemsplik PDF
pKa of monoprotic acidsplik PDF