A pH Calculator, a Virtual Titrator, a Real Titration Data Analyzer, a Distribution Diagram Generator - thats CurTiPot, the all-in-one freeware to learn, teach and work with chemical equilibrium of acids, bases, salts and buffers at home, classroom, interactive dry lab , routine or research laboratory. characteristics of this strong suite of MS Excel spreadsheets embrace: - pH calculation of any aqueous solution of strong and weak acids, bases, salts, buffers and mixtures of up to 7 polyprotic systems (>40 species), with activity coefficient estimation; - Simulation and overlay of acid-base titration curves of any complexity, with or without random errors in pH and/or volume. Valuable for teaching, generation of unlimited titration exercises and evaluation of the feasibility and accuracy of new titrations. - Analysis of pH vs. volume data from simulated and real potentiometric titration curves by two methods: i) graphical representation of curves, assisted by cubic splines interpolation and smoothing of derivative curves, for accurate evaluation of inflections (end-points); ii) determination of concentrations and refinement of pKa values by multiple nonlinear regression (based on the Solver supplement of Excel), essential for difficult titrations with undefined inflections, e.g., acid rain. - Generation of protonation curves and distribution diagrams of equilibrium species of acids and bases at equilibrium as a function of pH or of added volume of titrant. - Expandable database with pKa values of 250 acids and bases. Simply unzip the curtipot_.xls file, open it with Microsoft Excel, habilitate macros and start learning, working and teaching. No install/uninstall required, all macros are removed by closing file. The software is completely free for educational and non-commercial not-for-profit use.