Analytical Chemistry
A.Y. 2023/2024
Learning objectives
The course has the goal to provide the students the general bases of Analytical Chemistry enabling
them to operate within a laboratory of analytical chemistry. The course aims to introduce students to the understanding of equilibria in solution and of the main methods of analysis both from a theoretical point of view and from a more applicative point of view. The course also aims to make students able to acquire the critical ability in underestimating the accuracy and precision of experimental data through statistical methods, the ability to solve analytical problems related to complex equilibria in solution and quantitative analysis of compounds. The course also includes a single-seat laboratory teaching unit in which exercises will be carried out aimed at acquiring the notions that allow a correct conduct of a chemical analysis, including the elementary safety rules relating to handling and disposal and chemical products. The laboratory exercises are aimed at learning the basic knowledge of volumetric analysis (titration).
them to operate within a laboratory of analytical chemistry. The course aims to introduce students to the understanding of equilibria in solution and of the main methods of analysis both from a theoretical point of view and from a more applicative point of view. The course also aims to make students able to acquire the critical ability in underestimating the accuracy and precision of experimental data through statistical methods, the ability to solve analytical problems related to complex equilibria in solution and quantitative analysis of compounds. The course also includes a single-seat laboratory teaching unit in which exercises will be carried out aimed at acquiring the notions that allow a correct conduct of a chemical analysis, including the elementary safety rules relating to handling and disposal and chemical products. The laboratory exercises are aimed at learning the basic knowledge of volumetric analysis (titration).
Expected learning outcomes
At the end of the course the student acquires the notions of analytical chemistry necessary for: knowledge of the procedures for processing and evaluating experimental data; the knowledge of the main complex chemical equilibria in solution and the ability to independently solve simple analytical problems ranging from sampling, to 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 of analytical chemistry to describe and comment on an analytical method and report the result correctly and without ambiguity. The attendance of the laboratory will allow the student to be able 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).
Argentimetric titration, Mohr and Fajans argentimetric method (determination of chlorides in an unknown sample).
Potentiometric titration (in particular, pHmetry).
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).
Argentimetric titration, Mohr and Fajans argentimetric method (determination of chlorides in an unknown sample).
Potentiometric titration (in particular, pHmetry).
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 compulsory for both classroom and laboratory units (percentages will be communicated at the end of the course).
Teaching Resources
Analytical Chemistry and Quantitative Analysis (D. S. Hage and J. D. Carr) Publishing House: Piccin;
Fundamentals of Analytical Chemistry (Skoog & West) Publishing House: EdiSES;
Analytical Chemistry (V. Di Marco, P. Patore, G. G. Bombi) Publishing House: EdiSES.
Lecturer's handouts.
Fundamentals of Analytical Chemistry (Skoog & West) Publishing House: EdiSES;
Analytical Chemistry (V. Di Marco, P. Patore, G. G. Bombi) Publishing House: EdiSES.
Lecturer's handouts.
Assessment methods and Criteria
Written test lasting a total of three hours comprising open questions of varying length and short exercises and problems on the topics covered. The test is divided into a first part, of two and a half hours on the theoretical part of the course followed after a short interval by a second part, of forty minutes, on the laboratory part. The overall grade in thirtieths is given based on the sum of the points awarded for the first part (maximum 26 points) and the second part (maximum 5 points). Honours on the comprehensive examination requires not only excellent performance in theory part but also full marks in the laboratory part.
The student is only admitted to the written examination if he/she has handed in the Laboratory Reports in advance. The Laboratory Reports will be included in the final assessment.
The student is only admitted to the written examination if he/she has handed in the Laboratory Reports in advance. The Laboratory Reports will be included in the final assessment.
CHIM/01 - ANALYTICAL CHEMISTRY - University credits: 8
Practicals: 16 hours
Single bench laboratory practical: 32 hours
Lessons: 40 hours
Single bench laboratory practical: 32 hours
Lessons: 40 hours
Professors:
Comite Valeria, Panigati Monica
Educational website(s)
Professor(s)