66684 - Analytical Chemistry and Laboratory

Learning outcomes

At the end of the course, the student is capable of understanding the principles that define analytical chemistry as "problem-solving" with respect to volumetric and gravimetric methods. Furthermore, they have acquired necessary knowledge about simultaneous equilibria in solution to determine optimal conditions for the execution of volumetric and gravimetric determinations. The student has gained practical experience that enables them to perform quantitative volumetric determinations based on acid-base, redox, complexometric, and precipitation reactions, either in a classical manner or through potentiometry, on real samples. They can identify the most suitable methodologies for solving simple analytical problems and present and evaluate experimental data using basic statistical procedures.

Course contents

PREQUISITES 

1) Elementary functions: fractions, powers, roots, exponentials, and logarithms. Solution of algebraic equations

2) Knowledge of the main physical quantities and the relationships that bind them, main units of measurement

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

4) Knowledge of Thermodynamics applicable to systems of chemical interest under equilibrium conditions. Phase equilibria in single-component systems. The equation of perfect gases. Mole fraction and partial pressure. Basic electrochemistry.

THEORY PART

Fundamentals of Statistics in Analytical Chemistry: Quality of analytical data. Significant figures. Sources of uncertainty. Errors in chemical analysis; propagation of error. Gross errors, systematic errors, random errors. Accuracy and precision. Confidence interval. Significance test: Student's t. Accuracy test. Precision test. Comparison of two samples.

Fundamentals of Analytical Chemistry: Application of the concepts of mole, concentration, and dilution to the resolution of practical problems in analytical chemistry, particularly in the stoichiometry of solutions. Introduction to volumetric and gravimetric analysis methods. Exercises on the analytical process.

Acids and bases in aqueous solvents: The characteristic properties of chemical compounds at the core of analytical chemistry. Complex matrices and interference. Systematic treatment of chemical equilibria. graphical methods for the representation of chemical equilibria. Strength of acids and bases. Polyfunctional acids and bases. Buffer solutions and ampholyte solutions. pH calculations. Acid-base titrations. Methods for evaluating the equivalence point of a titration. Titration error.

Complexometry: Formation of complexes and pH. Conditional and thermodynamic constants. Complexometric titrations. EDTA and analytical applications. Interferents and masking.

Precipitation equilibria: Solubility and pH. Solubility and complexes. Precipitation titrations. Gravimetric analysis methods.

Redox equilibria: Electrochemical cells. Effects of pH, solubility equilibria, and complex formation on redox potential. Stability of redox systems in water. Redox titrations.

Potentiometry: Standard hydrogen electrode (SHE). Indicator and reference electrodes. Glass electrode for pH measurement. Potentiometric titrations.

Development of analytical methods: Introduction to the main regulatory and technical-scientific references (ISO, UNI, national standards, scientific literature) for the design of analytical procedures. Definition of analytical objectives, selection of the most suitable technique based on the matrix and the analytes of interest, drafting of detailed operating procedures. Discussion of practical examples on real samples and attention to validation aspects and compliance with current regulations.

LABORATORY PART

The topics from the theoretical part will be the subject of laboratory experiences, the aim of which will be to: i) put into practice the experimental analysis methods; ii) adapt specific analytical procedures to real samples.

Lectures

The recording of work in the laboratory. Volumetric glassware: characteristics, modes of use, calibration. Practical aspects of volumetric titrations: identification of the endpoint using indicators and with graphical and numerical methods. Primary standards. Error handling. Introduction to potentiometric methods.

Laboratory experiences

Laboratory activities include an initial phase of individual experiences aimed at refining each student's practical skills, followed by one or more group experiences designed to develop collaboration and teamwork abilities.

Calibration of glassware. Acid-base titrations: normalization of HCl and NaOH solutions; Acid-base titrations of real samples. Complexometric titrations: determination of the hardness of a real sample. Argentometry. Potentiometric acid-base titrations. Unknown titration.

Attendance at laboratory activities is mandatory in order to take the final exam.

Exercises

In addition to the laboratory experiments, students will need to perform the statistical treatment of the data obtained from experimental measurements, compiling a report based on a template, which will be subject to evaluation. Furthermore, students are required to fill out their individual laboratory notebooks during the experiments. The execution of laboratory activities requires the use of spreadsheets (Microsoft Excel) to perform data processing and simulate the experimental responses obtained.

Laboratory and theoretical activities dedicated to the development, design, and evaluation of analytical methods in the field of chemical analysis allow students to acquire skills in experimental planning, problem-solving applied to the analysis of real samples, data quality control, and the preparation of accurate technical documentation, which are fundamental elements for both professional practice in analytical chemistry and project management.

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

About the laboratory notebook:

Rebecca Milholland. Guide to keeping a laboratory notebook [https://www.niehs.nih.gov/sites/default/files/health/assets/docs_f_o/guide_to_keeping_laboratory_notebooks_2002_508.pdf] . National Institute of Health

Philip Ryan, Analyst Office of Intramural Training and Education. Keeping a Lab Notebook [https://biotechnology.rutgers.edu/sites/default/files/uploads/RESOURCES%20PAGE-Lab%20Notebook%20Presentation.pdf] . Presentation at a webinar of National Institute of Health

Teaching methods

Classroom lessons, supplemented by practical exercises on the topics covered. It is essential to supplement and deepen the material presented in class with individual study of the textbooks. It is also recommended to participate in classroom discussions on the topics covered and in the open forums on Virtuale. Theoretical teaching and laboratory work are closely integrated and interdependent. The study of the principles of analytical chemistry and the experimental work, where these are put into action, must necessarily coexist because the experimental activity facilitates the correct cognitive placement of the various topics addressed and encourages the gradual assumption of autonomy in laboratory practice.

Safety in the workplace

Attendance at the laboratory requires the completion of Modules 1 and 2 remotely and participation in Module 3, which focuses on specific training on safety and health in study environments. Indications on the dates and attendance methods for Module 3 can be found in the appropriate section of the course website.

Assessment methods

The verification of the acquired knowledge will be carried out through a final written exam. The score is combined with that obtained from the Laboratory of the Analytical Chemistry course (a single final grade). The written exam aims to assess the understanding of the topics covered in both courses.

The exam consists of a written test lasting 3 hours and includes exercises and open-ended questions. During the written exam, the use of textbooks and class notes (or slides) is not permitted. It is necessary to present yourself equipped with a calculator (the one available on devices like tablets or cell phones is not allowed) and the tools for drawing diagrams (pencils, ruler, set square, eraser). The material on which to write the tests (protocol sheets, graph paper, etc.) will be provided by the teacher.

Attendance at the laboratory is mandatory for admission to the final exam. A maximum of 2 absences in the laboratory part is allowed. Furthermore, it is mandatory to have submitted all the experience reports by the assigned deadlines.

To take the scheduled exams, registration through "AlmaEsami" is required, in strict adherence to the indicated deadlines.

Students who do not comply with the aforementioned obligations will not be able to register for the exam on AlmaEsami.

The final evaluation includes the integration of the theoretical part (60% of the final grade) with the Laboratory part. The evaluation of the Laboratory part is based on the reports of the conducted experiments (20% of the final grade) and the results obtained in an unknown Laboratory test (20% of the final grade). The laboratory test is based on a volumetric determination of an unknown solution. During the execution of the test, only the use of the laboratory notebook is allowed, and no other supporting materials (slides, handouts, etc.) are permitted. The lab grade is the average of the report grades and the final exam grade.

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

Students with learning disorders and\or temporary or permanent disabilities: please, contact the office responsible (https://site.unibo.it/studenti-con-disabilita-e-dsa/en/for-students) as soon as possible so that they can propose acceptable adjustments. The request for adaptation must be submitted in advance (15 days before the exam date) to the lecturer, who will assess the appropriateness of the adjustments, taking into account the teaching objectives.

Teaching tools

Educational activities make use of supports such as video projection, chemistry laboratories, data processing software, and the manual of experiments.

The presented educational material is available for the students.

Office hours

See the website of Isacco Gualandi

See the website of Sergio Zappoli

See the website of Federica Mariani