To enable students to become conversant with issues concerning equilibria in solution (acid-base, precipitation, complexation, redox).
Concepts acquired from this Module will then be used in the Laboratory Module.
To enable students to use autonomously the concepts acquired during the theoretical course (Module 1).
Lectures associated to the analysis of numerical problems. Problems are presented and illustrated by the teacher and sometimes by the students themselves upon request.
Lectures associated to practise exercises in laboratory.
Aim of the Course. Classification of the methods of analysis. Concentration units. Numerical examples.
Solution Equilibria. General principles. Gibbs energy and equilibrium constants. Factors influencing equilibrium constants; temperature, solvent, ionic strength. Activity and activity coefficients. Debye-Huckel's Law. Numerical examples. Acid-base equilibria. Strength of an acid. Mass, charge and proton balance equations. pH. Rigorous definition. Calculation of the pH of strong acids: rigorous equation and approximations. Approximation criterion. Numerical examples. Weak acids/bases. Calculation of the pH of weak bases: rigorous equation and approximations. Numerical examples. Mono- and two-color indicators: rigorous equations. Numerical examples.
Polyprotic acids: rigorous and approximate equations. Acid mixtures. Ampholytes. Distribution diagrams. Titration curves. Strong base with a strong acid, weak acid with a strong base, polyprotic acids. Numerical examples. Buffer solutions. Buffering capacity: rigorous equation. Numerical examples.
Precipitation equilibria. Solubility and solubility product. Factors influencing electrolyte solubility: temperature, solvent and ionic strength. Effect of a common ion, pH and formation of complexes. Titrations based on the formation of a precipitate. Error at the end point: rigorous equation. Numerical examples.
Complexation equilibria. Degree of formation. pH effect on complexation equilibria. Conditional constant. Metallochromic indicators. Choice of operational conditions. Complexometric titrations. Numerical examples.
Data treatment: outline. Experimental errors. Bias and random errors. Precision and accuracy. Sampling. Sample description. Position and dispersion parameters. Binomial distribution, Poisson distribution, normal distribution. Reduced normal. Main tests (Student test, F-test, χ2, Dixon’s test). Significant figure. Error propagation. Numerical examples.
This Module requires approximately 48 hrs, while the second Module requires 72 hrs; the total working time goes up since Students often ask for extra time for exercises outside the scheduled hours.
Please note: All the above arguments are deemed indispensable.
Laboratory. Choice of the analytical method. Instrumentation, precision, sensitivity. Result report.
Gravimetric analysis. Analysis through precipitation. Precipitate formation. Nickel determination by DMG.
Titrations: general principles. Preparation of standard solutions. Primary standards. Standardization procedure.
Acid-Base titrations. Na2B4O7.10H2O in acidimetric titrations. Determination of the titre of acids/bases commonly employed in a laboratory.
Precipitation titrations. Argentometry. Chloride determination according to Mohr and Fajans. Chloride/Carbonate separation
Complexometric titrations. EDTA titrations. Determination of Cu2+.
Redox titrations. Permanganometry. Determination of Fe2+ and H2O2. Iodometry. Determination of Cu2+.
1. Kolthoff, Sandell, Meehan e Bruckenstein - Analisi Chimica Quantitativa. Vol. 1 e Vol. 2, Piccin Editore.
2. E. De Simoni - Chimica Analitica, CUL (Bologna).
3. Skoog & West - Chimica Analitica. S.E.S.
4. D. H. Harris - Chimica Analitica quantitativa, Zanichelli.
5. Freiser e Fernando - Gli equilibri ionici della Chimica Analitica. Piccin Editore.
6. J. N. Butler - Ionic Equilibrium: Solubility and pH Calculations, Wiley
Kolthoff, Sandell, Meehan e Bruckenstein - Analisi Chimica Quantitativa. Vol. 1 e Vol. 2, Piccin Editore.
Vogel - Analisi Chimica Quantitativa. Vol. 1 e Vol. 2, J. H. Jeffery, J. Bassett, J. Mendham, R. C. Denney Editori, CEA
Slides provided by the lecturer