66684 - Analytical Chemistry and Laboratory

Learning outcomes

At the end of the course, the student will acquire the principles defining analytical chemistry from the point of view of the "problem solving" approach, in particular applied to volumetric and gravimetric analysis. Furthermore, the student will have knowledge about: chemical equilibria in solution with particular attention to the simultaneous ones with the aim of carrying out simple qualitative tests and of defining the optimal conditions for an analytical determination. The student’s skills will be particularly focused on materials of industrial interest and will allow to carry out quantitative volumetric determinations in a classical way or potentiometrically. The student will be able to identify the most suitable methodologies for solving simple analytical issues, to present and to evaluate experimental data by applying basic statistical procedures. The student will also be able to fill an analysis report correctly.

Course contents

Prerequisites

1) Elementary functions: fractions, powers, roots, exponentials and logarithms. Solution of algebraic equations. Basic knowledge of differential and integral calculus for functions having one real variable.

2) Knowledge of the main physical quantities and the relationships among them, main units of measurement. Basic knowledge of electromagnetism.

3) Chemical reactions and their balancing. Concept of mole. Solutions and concentration units. Le Chatelier's concept of balance and principle. Stoichiometric calculations for complete and equilibrium reactions. Knowledge of the chemism of the most common elements and compounds. Knowledge of basic nomenclature and formulas.

4) Knowledge of Thermodynamics applicable to systems of chemical interest in equilibrium conditions. Phase equilibria in single-component and multi-component systems.

The equation of ideal gases. Molar fraction and partial pressure. Basic electrochemistry.

Theoretical Course

Fundamentals of statistics in analytical chemistry: Quality of analytical data. Significant figures. Sources of uncertainty. Errors in chemical analysis. Gross, systematic and random errors. Accuracy and precision. Propagation of errors. Methods for reporting analytical data. Significance tests: Student's t parameter. Test for evaluating accuracy. Test for evaluating precision. Comparison of two experimental means. Calibration and measurement. Linear regression. Concept of detection limit.

Fundamentals of analytical chemistry: titrations, gravimetric analysis, exercises on the analytical processes.

Acids and bases in aqueous solvents: Strength of acids and bases. Polyfunctional acids and bases. Ampholytes. Buffer solutions. Systematic approach to the chemical equilibria. pH calculations. Acid-base titration methods for estimating the equivalent point. Titration error. Effects of the solvent in acid-base reactions.

Solubility equilibria: Solubility as a function of pH. Precipitation titrations.

Complex formation: Complexation as a function of pH. Conditional and thermodynamic constants. Complexometric titrations. EDTA and analytical applications. Interferences and masking.

Redox equilibria in homogeneous phase: Electrochemical cells. Influence of pH, solubility and complex formation on the redox potential. Stability of redox systems in water. E/pH diagrams. Redox titrations.

Potentiometry: Direct and indirect measurements. Indicator and reference electrodes. Ion selective electrodes. Potentiometric titrations.

LABORATORY COURSE

Frontal lessons

Tracking laboratory activity. The volumetric glassware: characteristics, use, calibration. Practical features of volumetric titrations: determination of endpoint by means of indicators or graphical and numerical methods. Primary standards. Error analysis. Introduction to potentiometry. Analysis of real samples.

Lab activity

Acid-base titrations: standardization of HCl and NaOH solutions; acid-base titrations of real samples. Complexometric titrations: determination of the hardness of a real water sample. Argentometric titrations. Potentiometric acid-base titrations.

Numerical exercises

Besides the laboratory experiments the students will have to conduct the statistical treatment of the experimental data obtained during their Lab activity. The students have to fill their own laboratory notebook, recording their activities and results.

Readings/Bibliography

D.A. Skoog, D.M. West, F.J. Holler, S.R. Crouch, Fondamenti di Chimica Analitica. EdiSES, Napoli, 2005.

D.C. Harris, Chimica Analitica Quantitativa, Zanichelli, Bologna, 2005

Teaching methods

Lectures integrated by exercises related to the discussed topics. Individual study on text books and team-discussion on the arguments under study are encouraged. The Course is integrated with laboratory activity. Theory and laboratory work must co-exist since practice not only develops the capability of the student to think but also to act independently. In consideration of the types of activities and teaching methods adopted, the attendance of the laboratory requires all students to carry out e-learning of Modules 1 and 2 and to participate in Module 3 for specific training on safety and health in the study areas. Information on dates and methods of attendance of Module 3 can be consulted in the specific section of the degree program website.

Assessment methods

The assessment of the acquired knowledge will be carried out through a final written exam. The score is integrated with that obtained from the Laboratory of the Analytical Chemistry course (only one final mark). The written examination aims to verify the acquisition of the learning outcomes expected from the knowledge of the topics which constitute the programs of both Courses.

The exam is a written test lasting 3 hours. The written test aims to ascertain the acquisition of the knowledge and skills required by the course program by solving exercises and answering open questions. During the written test, the use of textbooks and lecture notes (or slides) is not allowed. It is mandatory to bring a calculator (the one available on tablet or mobile devices is not allowed) and all the necessary to draw diagrams (pencils, ruler, square, eraser). The material on which the student will write the tests (sheets, graph paper, etc.) will be made available by the teacher.

The final evaluation will be integrated with the mark of the Analytical Chemistry Laboratory Course (single grade), which is given based on the reports associated with each lab experience and the final Laboratory test. The final laboratory test will be a titration of an unknown solution, and during the test the use of the laboratory notebook is allowed, while slides or other handouts are not allowed. The laboratory mark will be the average among the report grades and the final lab exam grade.

The exam is passed if the score obtained in the written test will be greater than or equal to 18/30; in this case the final score will be determined by the average, weighted on the basis of the assigned credits, of the scores obtained in the written test and in the laboratory activity.

Teaching tools

Lectures and class-room activities are carried out with the help of video-projection, Laboratories, softwares for data treatment, experiences booklet.

The teaching material is available to the students. The experimental work will be carried out in the Analytical Chemistry Laboratory.

Office hours

See the website of Isacco Gualandi

See the website of Federica Mariani