Analytical Chemistry
A.Y. 2024/2025
Learning objectives
The course aims to provide students with the general foundations of Analytical Chemistry by providing both theoretical and applied knowledge to operate correctly in an analytical chemistry laboratory. The course aims to introduce students to the understanding of equilibria in solution and the main methods of analysis. The course also aims to provide students with critical skills in evaluating the accuracy and precision of experimental data using statistical methods, the ability to solve analytical problems related to complex equilibria in solution and quantitative analysis of compounds. The course also includes laboratory exercises conducted at individual workstations, aimed at acquiring the knowledge necessary for conducting chemical analyses correctly, including basic safety protocols for handling and disposing of chemicals. These exercises focus on learning the fundamentals of volumetric analysis (titration).
Expected learning outcomes
At the end of the course, the student will have acquired the knowledge of analytical chemistry necessary for the knowledge of the principles on which the most commonly used analytical techniques in the chemical, chemical-toxicological and food fields are based; the knowledge of the procedures for processing and evaluating experimental data; the knowledge of the main complex chemical equilibria in solution and the ability to autonomously solve simple analytical problems ranging from sampling, sample treatment, up to the type of analytical method chosen (among those studied) for the quantification of the analytes, taking into account the uncertainty of measurement; the ability to use the specific language proper to Analytical Chemistry this to describe and comment on an analytical method and to report the result correctly and unambiguously. Attendance at the laboratory will enable the student to be able to operate safely in chemical laboratories and to perform standard laboratory procedures for the recognition and quantification of simple analytical species.
Lesson period: Second semester
Assessment methods: Esame
Assessment result: voto verbalizzato in trentesimi
Single course
This course can be attended as a single course.
Course syllabus and organization
Single session
Responsible
Lesson period
Second semester
Course syllabus
Sampling and analysis methods: sampling, sampling strategies, sampling techniques, sample storage, standardisation, calibration.
Treatment and evaluation of statistical data: errors in chemical analysis, sources and treatment of error in the analytical process, characteristics of an analytical method (accuracy and precision), error propagation and significant figures, statistical treatment of error, confidence intervals, variance analysis, standard deviation, relative standard deviation, standard deviation of the mean.
Classification of chemicals: hazard symbols on containers and packaging. Description of the main glassware used in the laboratory.
Acid-base equilibria: acid and base pH calculation: strong, weak, mono and polyprotic, pure and in mixtures - systematic treatment and approximations. Main species, distribution function, distribution diagram.
Amphiprotic species: pH calculation.
Buffer solutions: Henderson-Hasselbalch equation, approximations in pH calculation.
Introduction to acid-base titrations and acid-base indicators.
Complexes: formation and instability constants, partial and global. Systematic treatment of complexation equilibrium. Main species (as a function of [L]). Distribution function (β= f [L]). Distribution diagram - effect of K-value on diagram. Examples of concentration calculations: species in solution and solubility of poorly soluble species in complexation equilibria. Stability of a complex and pH. Conditional constant. Examples of the use of complexes in analysis (coloured complexes, solubilisation, masking).
Multidentate ligands: metal-EDTA complexes. Conditional constant. Use of EDTA.
Introduction on complexometric titrations and metallochromic indicators.
Precipitation equilibria: solubility and solubility product. Common ion effect. Effect of competitive equilibria. Precipitation reactions. Separations by fractional precipitation. Precipitation equilibria: calculation of the solubility of a salt whose anion is the conjugate base of a weak acid, at a known pH.
Introduction to precipitation titrations and indicators.
Precipitation reactions from constant pH solutions.
Redox equilibria: similarities and differences between acid-base, complexation and redox equilibria.
Description of galvanic cells: schematic representation of a cell, description of the standard hydrogen electrode and its application, Nernst equation and its application, calculation of redox equilibrium constants.
Calculation of thermodynamic cell potentials.
Application of reduction potentials: redox titration curves, permanganometry, potassium dichromate titrations, iodometric titrations.
Description of redox indicators, auxiliary oxidising reagents, auxiliary reducing reagents, Jones and Walden reducing agents.
Potentiometry: schematic of a typical cell for potentiometric analysis.
Description of junction potential.
Reference electrodes: calomel, silver/silver chloride and calculation of their potentials.
Description of indicator electrodes: metal electrodes (first, second, third and fourth species), glass electrode (determination of membrane potential, interphase potential, consequences of alkaline and acid error), crystalline membrane electrodes, gas electrodes.
EXERCISE:
Exercises on the topics covered in the classroom.
LABORATORY MODULE
Basic instructions on how to work in an analytical laboratory and on how to carry out the planned experiments. Use of burette, pipette, rubber bulb, pipette/plug calibration.
Titrations with colorimetric indicators: acid base (HCl with NaOH, acetic acid in vinegar).
Complexation titration (total water hardness with EDTA).
Redox titration (iodometric determination of ascorbic acid, determination of iron content in an unknown sample with permanganate).
Treatment and evaluation of statistical data: errors in chemical analysis, sources and treatment of error in the analytical process, characteristics of an analytical method (accuracy and precision), error propagation and significant figures, statistical treatment of error, confidence intervals, variance analysis, standard deviation, relative standard deviation, standard deviation of the mean.
Classification of chemicals: hazard symbols on containers and packaging. Description of the main glassware used in the laboratory.
Acid-base equilibria: acid and base pH calculation: strong, weak, mono and polyprotic, pure and in mixtures - systematic treatment and approximations. Main species, distribution function, distribution diagram.
Amphiprotic species: pH calculation.
Buffer solutions: Henderson-Hasselbalch equation, approximations in pH calculation.
Introduction to acid-base titrations and acid-base indicators.
Complexes: formation and instability constants, partial and global. Systematic treatment of complexation equilibrium. Main species (as a function of [L]). Distribution function (β= f [L]). Distribution diagram - effect of K-value on diagram. Examples of concentration calculations: species in solution and solubility of poorly soluble species in complexation equilibria. Stability of a complex and pH. Conditional constant. Examples of the use of complexes in analysis (coloured complexes, solubilisation, masking).
Multidentate ligands: metal-EDTA complexes. Conditional constant. Use of EDTA.
Introduction on complexometric titrations and metallochromic indicators.
Precipitation equilibria: solubility and solubility product. Common ion effect. Effect of competitive equilibria. Precipitation reactions. Separations by fractional precipitation. Precipitation equilibria: calculation of the solubility of a salt whose anion is the conjugate base of a weak acid, at a known pH.
Introduction to precipitation titrations and indicators.
Precipitation reactions from constant pH solutions.
Redox equilibria: similarities and differences between acid-base, complexation and redox equilibria.
Description of galvanic cells: schematic representation of a cell, description of the standard hydrogen electrode and its application, Nernst equation and its application, calculation of redox equilibrium constants.
Calculation of thermodynamic cell potentials.
Application of reduction potentials: redox titration curves, permanganometry, potassium dichromate titrations, iodometric titrations.
Description of redox indicators, auxiliary oxidising reagents, auxiliary reducing reagents, Jones and Walden reducing agents.
Potentiometry: schematic of a typical cell for potentiometric analysis.
Description of junction potential.
Reference electrodes: calomel, silver/silver chloride and calculation of their potentials.
Description of indicator electrodes: metal electrodes (first, second, third and fourth species), glass electrode (determination of membrane potential, interphase potential, consequences of alkaline and acid error), crystalline membrane electrodes, gas electrodes.
EXERCISE:
Exercises on the topics covered in the classroom.
LABORATORY MODULE
Basic instructions on how to work in an analytical laboratory and on how to carry out the planned experiments. Use of burette, pipette, rubber bulb, pipette/plug calibration.
Titrations with colorimetric indicators: acid base (HCl with NaOH, acetic acid in vinegar).
Complexation titration (total water hardness with EDTA).
Redox titration (iodometric determination of ascorbic acid, determination of iron content in an unknown sample with permanganate).
Prerequisites for admission
Knowledge of basic mathematics, knowledge of general chemistry and stoichiometry
Teaching methods
The course consists of three teaching units: lectures, classroom exercises, and practical laboratory exercises. Attendance is mandatory for both the classroom teaching units and the laboratory (the allowable absence percentages will be communicated at the end of the course).
Teaching Resources
Analytical Chemistry and Quantitative Analysis (D. S. Hage and J. D. Carr) Publisher: Piccin;
Fundamentals of Analytical Chemistry (Skoog & West) Publisher: EdiSES;
Analytical Chemistry (V. Di Marco, P. Patore, G. G. Bombi) Publisher: EdiSES. Lecturer's handouts.
Fundamentals of Analytical Chemistry (Skoog & West) Publisher: EdiSES;
Analytical Chemistry (V. Di Marco, P. Patore, G. G. Bombi) Publisher: EdiSES. Lecturer's handouts.
Assessment methods and Criteria
The written exam, lasting a total of three hours, includes open-ended questions of varying lengths as well as short exercises and problems on the topics covered. The exam is divided into two parts: the first part, lasting 2 hours, covers the theoretical portion of the course, followed by a short break and then the second part, lasting 1 hour, covers the laboratory portion. The overall grade, out of thirty, is based on the sum of the scores from the first part (maximum 25 points) and the second part (maximum 5 points). To pass the exam, it is necessary to obtain at least 17 points in the first part and at least 4 points in the second part. Honors for the entire exam require not only an excellent score in the theoretical part but also a perfect score in the laboratory part.
Students are allowed to take the written exam only if they have previously submitted the Laboratory Reports. The Laboratory Reports will be included in the final evaluation.
Students are allowed to take the written exam only if they have previously submitted the Laboratory Reports. The Laboratory Reports will be included in the final evaluation.
CHIM/01 - ANALYTICAL CHEMISTRY - University credits: 6
Practicals: 16 hours
Single bench laboratory practical: 16 hours
Lessons: 32 hours
Single bench laboratory practical: 16 hours
Lessons: 32 hours
Professor:
Comite Valeria
Professor(s)