ANALYTICAL CHEMISTRY I AND LABORATORY A - L

Learning Objectives

• MODULO 1

  At the end of the course, the student should be able to calculate the chemical composition of an aqueous solution in presence of Broensted acid-base equilibria and/or complexation equilibria and/or precipitation-solubility equilibria.

• MODULO 2

  The course aims to provide students with fundamental tools for quantitative analysis based on ionic equilibria in solution through the employment of the most significant gravimetric and volumetric methods in analytical chemistry. The purpose of the course is to give a global vision of the analytical process from the selection of the method of analysis to data processing and critical discussion of the results.

  Knowledge and understanding:

  Understanding the basic concepts of the classical methods of volumetric and gravimetric analysis as well as of their applications. Knowledge of the basis of statistics for the treatment of experimental data.

  Applying knowledge and understanding:

  Development of tools for understanding the methods and procedures for quantitative chemical analysis as well as acquisition of the practical skills for volumetric and gravimetric methods through experiments in the laboratory. Development of a critical thinking for the presentation of the analytical data obtained.

  Making judgements:

  Ability to independently solve an analytical problem using volumetric/gravimetric methods as well as ability to interpret experimental data on the basis of the acquired knowledge and laboratory experiments.

  Communication skills:

  Acquiring proper language skills and ability to rigorously expose the topics covered in the course.

  Learning skills:

  Capability to develop tools and skills to successfully undertake further study paths with a high level of autonomy.

Course Structure

• MODULO 1

  Lectures and numerical exercices.

  Should teaching be carried out in mixed mode or remotely, it may be necessary to introduce changes with respect to previous statements, in line with the programme planned and outlined in the syllabus.

  Learning assessment may also be carried out on line, should the conditions require it.

• MODULO 2

  Class lectures, exercises, presentation of the lab experiments, treatment of the analytical data. Experiments in laboratory on volumetric and gravimetric analysis.

  Should teaching be carried out in mixed mode or remotely, it may be necessary to introduce changes with respect to previous statements, in line with the programme planned and outlined in the syllabus.

Detailed Course Content

• MODULO 1

  Introduction - Chemical equilibrium – Equilibrium constant – Factors affecting the equilibrium constant; composition, solvent, temperature. Systematic treatment of equilibrium. Mass, charge and proton balances.

  Acid-base equilibria – Broensted and Lewis theories – Conjugate acid-base pair – Strength of acids and bases – Water ionic product and pH – Acidity and neutrality of an aqueous solution - Strong acids or strong bases aqueous solution; rigorous and approximate treatments; criteria and validity limits – Weak monoprotic acids or weak monoacid bases aqueous solution; dissociation degree; rigorous and approximate treatments; criteria and limits of validity – Aqueous solution containing one conjugate polyprotic acid or one polyacid base; rigorous and approximate treatments - Composition vs. pH expression; distribution plot - Aqueous solution containing a conjugate acid-base pair; rigorous and approximate treatments; buffers; buffer capability – Aqueous solution containing a conjugate polyprotic acid - polyacid base pair –– Ampholytes - Aqueous solution containing mixture of acids and bases (strong-strong, weak-strong, strong-weak, weak-weak); rigorous and approximate treatments.

  Complex formation equilibria – monodentate and polydentate ligands, chelate effect, partial formation , global formation and conditional formation constants, pH influence.

  Precipitation equilibria - Solubility and solubility product - Selective precipitation, gravimetry - Influence of Broensted and Lewis acid-base interaction on the solubility of salts containing monovalent and polyvalent cations and anions.

  Activity - Relationship between activity and concentration – Thermodynamic and stoichiometric constants – Ionic strength – Short outline of Debye Hückel theory and its practical application on ionic equilibrium.

  Volumetric methods; generality, titration graphs, end-point indicators.

  • Acid-base titrations; strong acid, strong base, weak acid, weak base, polyprotic acid, polyacid base - Titration criteria - Acid-base indicators - Titration error.
  • EDTA complexation titrations; pH choice, auxiliary complexing agents, indicators, titration error – Liebig titration.
  • Precipitation titration: generality - Silver nitrate as precipitation agent - Visualization of titration end-point by Möhr, Volhardt and Fajans methods - Titration error.
• MODULO 2

  Introduction. Elements of statistics. Errors in analytical chemistry. Presentation of data and results. Position and dispersion index. Most common statistical tests.

  Analytical measurement instrumentations. Precision, accuracy, sensitivity. Laboratory apparatuses: analytical balance and calibrated glassware.

  Volumetric analysis. General principles on titrations. Preparation of standard solutions. Primary standards. Standardization procedures. Acid-base titrations. Indicators. Acidimetric and alkalimetric determination of sodium tetraborate.

  Precipitation titrations. Determination of chloride by Mohr, Fajans, and Volhard methods. Carbonate/chloride separation.

  Gravimetric analysis. Analysis by precipitation. Formation, nature and size of precipitates. Gravimetric determination of Ni²⁺ as the bis-dimethylglioximate complex.

  Complexometric titrations. EDTA titrations. Metallochromic indicators. Determination of Cu²⁺.

  Redox titrations. Methods based on the use of permanganate. Determination of Fe²⁺. Iodometry. Determination of Cu²⁺.

Textbook Information

• MODULO 1

  - Daniel Harris - Quantitative Chemical Analysis, 9th edition, W.H. Freeman and Company, New York, 2016

  - Douglas A. Skoog, Donald M. West, F. James Holler, Stanley H. Crouch - Foundamentals of Analytical Chemistry, 9th edition, Brooks/Cole, Cengage Learning, 2014

• MODULO 2

  1. I. M. Kolthoff, E. B. Sandell, E. J. Meehan, S. Bruckenstein, “Analisi Chimica Quantitativa”, Piccin, Padova.

  2. D. C. Harris, "Chimica Analitica quantitativa", terza ed., Zanichelli, Bologna.

  3. F. J. Holler, S. R. Crouch, “Fondamenti di Chimica Analitica”, terza ed., Edises, Napoli.

  4. M. Garetto, "Statistica, lezioni ed esercizi", Università di Torino.

  5. E. De Simoni, "Chimica Analitica", CUL, Bologna.