Analytical Chemistry
A.Y. 2020/2021
Learning objectives
The course has the goal to provide the students the general bases of Analytical Chemistry and the general analytical methods enabling them to operate within a laboratory of analytical chemistry. The present course aims to introduce students to equilibria in aqueous solution both from a theoretical and practical point of view, introducing titrations and applying these latter to different types of analyses.
Expected learning outcomes
At the end of the course each student will be able to autonomously solve simple analytical problems ranging from sampling, to sample processing, to analytical method choise (among those studied) for analytes quantification, taking into account uncertainty of measurement.
Lesson period: Second semester
Assessment methods: Esame
Assessment result: voto verbalizzato in trentesimi
Single course
This course cannot be attended as a single course. Please check our list of single courses to find the ones available for enrolment.
Course syllabus and organization
Single session
Responsible
Lesson period
Second semester
In the case of impossibility to carry out the lessons in person, they will be held on the Teams platform on scheduled timetable. The recorded lessons can be also downloaded from the Ariel platform.
The program and reference material will not change.
Where the regulations allow it, the exam will take place in person, otherwise the written test will take place remotely using the Teams platform.
As far as the laboratory is concerned, if it is not possible to carry out the activities in person, videos developed by the teacher will be made available on Ariel.
The program and reference material will not change.
Where the regulations allow it, the exam will take place in person, otherwise the written test will take place remotely using the Teams platform.
As far as the laboratory is concerned, if it is not possible to carry out the activities in person, videos developed by the teacher will be made available on Ariel.
Course syllabus
Lectures:
Significant figures
Introduction to statistics
Uncertainty in analytical measurements
Aqueous solutions
Balance systems
Systematic treatment of balances: charge, mass, proton and electron balances. Examples of calculation in complex systems.
Acid-base equilibria: calculation of the pH of bases and acids, strong and weak, mono and polyprotic, pure and in mixtures - systematic treatment and approximations. Main species, distribution function, distribution diagram.
Amphiprotic species: pH calculation. Calculation of pH of single salt solutions.
Buffer solutions: Henderson-Hasselbalch equation, approximations in the calculation of pH. Buffering capacity. Examples of calculation of the buffering capacity. Buffer selection and preparation. Notes on acid-base titrations and acid-base indicators.
The complexes: formation and instability constants, partial and global. Systematic treatment of the complexing balance. Main species (depending on [L]). Distribution function (β = f [L]). Distribution diagram - effect of the K value on the diagram. Examples of calculating the concentration of species in solution and the solubility of poorly soluble species in the presence of complexation equilibria. Stability of a complex and pH. Conditional constant. Examples of use of the complexes in analysis (colored complexes, solubilization, masking).
Multidentate binders: metal complexes - EDTA. Conditional constant. Use of EDTA. Outline of complexometric titrations and metallochromic indicators.
Precipitation equilibria: solubility and solubility product. Common ion effect. Effect of competitive balances. 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, with a known pH. Notes on precipitation titrations and indicators.
Precipitation reactions from solutions with constant pH
Redox equilibria: analogies 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 the redox equilibrium constants, construction of the redox equilibrium distribution diagrams, calculation of the distribution fractions .
Solutions of redox pairs in the presence of competitive equilibria: competitive precipitation equilibria, competitive complexation equilibria, competitive acid-base equilibria.
Calculation of thermodynamic cell potentials.
Application of reduction potentials: redox titration curves, permanganometry, chromium titrations, iodometric titrations.
Description of: redox indicators, auxiliary oxidizing reagents, auxiliary reducing reagents, Jones and Walden reducers.
Expression of the concentration of a solution of hydrogen peroxide in volumes of oxygen.
Expression of the concentration of a hypochlorite solution in active chlorine.
Potentiometry: scheme of a typical cell for potentiometric analysis.
Description of the junction potential.
Reference electrodes: calomel, silver / silver chloride and calculation of their potentials.
Description of the 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, electrodes for gas analysis.
Classroom exercises:
Exercises on the topics covered in the lectures' unit.
Practical laboratory exercises:
Determination of the percentage by weight of acetic acid in a vinegar by colorimetric and pHmetric titration;
determination of the Kps of a salt by titration;
determination of the hardness of a drinking water;
determination of the acidity of lemon juice;
titration of a mixture of bases;
qualitative identification of some cations and anions;
identification of cations and anions in an unknown sample
Significant figures
Introduction to statistics
Uncertainty in analytical measurements
Aqueous solutions
Balance systems
Systematic treatment of balances: charge, mass, proton and electron balances. Examples of calculation in complex systems.
Acid-base equilibria: calculation of the pH of bases and acids, strong and weak, mono and polyprotic, pure and in mixtures - systematic treatment and approximations. Main species, distribution function, distribution diagram.
Amphiprotic species: pH calculation. Calculation of pH of single salt solutions.
Buffer solutions: Henderson-Hasselbalch equation, approximations in the calculation of pH. Buffering capacity. Examples of calculation of the buffering capacity. Buffer selection and preparation. Notes on acid-base titrations and acid-base indicators.
The complexes: formation and instability constants, partial and global. Systematic treatment of the complexing balance. Main species (depending on [L]). Distribution function (β = f [L]). Distribution diagram - effect of the K value on the diagram. Examples of calculating the concentration of species in solution and the solubility of poorly soluble species in the presence of complexation equilibria. Stability of a complex and pH. Conditional constant. Examples of use of the complexes in analysis (colored complexes, solubilization, masking).
Multidentate binders: metal complexes - EDTA. Conditional constant. Use of EDTA. Outline of complexometric titrations and metallochromic indicators.
Precipitation equilibria: solubility and solubility product. Common ion effect. Effect of competitive balances. 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, with a known pH. Notes on precipitation titrations and indicators.
Precipitation reactions from solutions with constant pH
Redox equilibria: analogies 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 the redox equilibrium constants, construction of the redox equilibrium distribution diagrams, calculation of the distribution fractions .
Solutions of redox pairs in the presence of competitive equilibria: competitive precipitation equilibria, competitive complexation equilibria, competitive acid-base equilibria.
Calculation of thermodynamic cell potentials.
Application of reduction potentials: redox titration curves, permanganometry, chromium titrations, iodometric titrations.
Description of: redox indicators, auxiliary oxidizing reagents, auxiliary reducing reagents, Jones and Walden reducers.
Expression of the concentration of a solution of hydrogen peroxide in volumes of oxygen.
Expression of the concentration of a hypochlorite solution in active chlorine.
Potentiometry: scheme of a typical cell for potentiometric analysis.
Description of the junction potential.
Reference electrodes: calomel, silver / silver chloride and calculation of their potentials.
Description of the 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, electrodes for gas analysis.
Classroom exercises:
Exercises on the topics covered in the lectures' unit.
Practical laboratory exercises:
Determination of the percentage by weight of acetic acid in a vinegar by colorimetric and pHmetric titration;
determination of the Kps of a salt by titration;
determination of the hardness of a drinking water;
determination of the acidity of lemon juice;
titration of a mixture of bases;
qualitative identification of some cations and anions;
identification of cations and anions in an unknown sample
Prerequisites for admission
Basic mathematics knowledge (algebra, first and second degree algebric equations, logarithms), knowledge of general chemistry and stoichiometry.
Teaching methods
The course consists of three teaching units: lectures, classroom exercises, practical exercises in the laboratory. Attendance is strongly recommended for classroom teaching units, compulsory for the laboratory.
Teaching Resources
Analytical Chemistry and Quantitative Analysis - D.S. Hage and J.D.Carr. Piccin Editor.
Basic Analytical Chemistry - Skoog&West
Chimica Analitica (V. Di Marco, P. Patore, G. G. Bombi) Casa Editrice: EdiSES.
Basic Analytical Chemistry - Skoog&West
Chimica Analitica (V. Di Marco, P. Patore, G. G. Bombi) Casa Editrice: EdiSES.
Assessment methods and Criteria
Written test. The student is admitted to the written exam only if he/she has previously delivered the Laboratory Report. The Laboratory Report will be part of the final evaluation.
Unità didattica: esercitazioni
CHIM/01 - ANALYTICAL CHEMISTRY - University credits: 3
Practicals: 16 hours
Single bench laboratory practical: 32 hours
Single bench laboratory practical: 32 hours
Professors:
Comite Valeria, Santagostini Laura
Unità didattica: lezioni
CHIM/01 - ANALYTICAL CHEMISTRY - University credits: 5
Lessons: 40 hours
Professor:
Falletta Ermelinda
Professor(s)
Reception:
By appointment
Office
Reception:
By appointment sending an e-mail
Dip. Chimica - Corpo A, Floor 0, Room R107