Course program
Analytical Problems and Their Solutions - Protocol
Basic concepts regarding the role of analytical chemistry and its applications. Analytical work protocol: method selection, sampling, pre-measurement analytical methodology (sample attack and separation). Analytical work protocol. Classic and instrumental tests. Treatment of obtained data. Solution equilibria, kinetic aspects, and thermodynamics (3 h)
Redox Reactions and Acidity
Homogeneous phase equilibria (acid-base, redox). Nernst equation. Factors influencing the kinetics of a chemical reaction. Redox reactions and acidity. Selective recognition of halides with permanganate. Case study of the nitrite/nitric oxide pair. Disproportionation and pH (case study of halogens and hydrogen peroxide). (4 h)
Complexes, Acidity, and Redox Reactions
A brief overview of complexes. Factors influencing the stability of a complex (dilution, medium, ionic strength). pH effect on complexes derived from weak acids. Changes in redox properties due to complex formation. Influence of instability constant on potential. The potential of a pair of ions, both complexing. Case study of manganese (III). (3 h)
Precipitation, Solubility, and Acidity Equilibria
Heterogeneous phase equilibria. Concept of solubility product, relationship between Ksp and solubility. Factors influencing the solubility of a slightly soluble compound (ionic strength, activity, medium, dilution, pH, common ion effect). Solubility of a slightly soluble compound from a weak monoprotic acid. Chemistry of sulfates, carbonates, oxalates. Chemistry of sulfides, calculation of the precipitation pH of a sulfide. Dissolution of a sulfide. Dissolution of sulfides via formation of salts and thio-salts, dissolution via acid-base and redox mechanisms. Solubility of a generic sulfide at any pH value. Hydroxide chemistry, the case of aluminum hydroxide (amphoteric) and zinc hydroxide. Amphoterism of hydroxides. Causes of amphoterism. Solubility of amphoteric hydroxides as a function of pH. Precipitate formation. Formation of colloidal precipitates, adsorption rules, aging of precipitates, post-precipitation. (10 h)
Solubility and Complexes
Precipitation of an insoluble compound from a complex. Reactions of thio-compounds. Dissolution of a precipitate via complex formation. (2 h)
Precipitation and Redox Reactions
Oxidations and precipitations. The case of the Fe2+/Fe3+ pair. Variation of redox properties due to salt precipitation. Stabilization of an oxidation state via precipitation (mercury chemistry). Complexes and precipitation. Disproportionation induced by the formation of a precipitate. (2 h)
Classification of Separation Methods
Liquid-liquid extraction. Phase distribution and Nernst's law: concept of distribution constant, distribution ratio. Theoretical principles of extraction. Efficiency and selectivity of an extraction. Factors involved in extraction equilibria. Extractability of weak acids and bases. Separation techniques and related physicochemical principles. Extractability of a cation, pH dependence. Logarithmic curves. (4 h)
Laboratory Activities
Safety in the laboratory. Explanation of experiments and discussion of observed phenomena (2 h)
Laboratory Exercises
5 CFU
Prerequisites
It is important to have acquired basic knowledge of chemical language and basic knowledge of acid-base reactions, the concept of pH, the concept and calculation of oxidation numbers, redox reactions, and balancing redox reactions from previous courses. It is also useful to know the distinction between electrolytes and non-electrolytes, between strong and weak electrolytes, and to have basic notions regarding the description of a chemical equilibrium, through the respective equilibrium constant and Le Chatelier's principle.
Frequency
Attendance at lectures is not mandatory for taking the exam but is strongly recommended. Attendance at laboratory exercises is mandatory
Exam mode
At the end of the course, students will undergo an oral exam, which must be booked through the INFOSTUD website: https://stud.infostud.uniroma1.it/Sest/Log/. The exam session dates are determined at the beginning of each academic year. Exams begin after the teaching activities of individual courses have concluded.
To pass the exam, students must achieve a grade not lower than 18/30. The final grade is unique and guarantees the acquisition of 9 CFU. The assessment method involves evaluating the student's ability to solve chemical problems, such as the separation of multiple inorganic analytes in a complex mixture, using the knowledge provided by the instructor. The evaluation takes into account laboratory attendance and, most importantly, the student's reasoning ability in addressing an analytical chemistry problem (logic followed by the student in solving the problem; correctness of the procedure identified for solving the problem; adequacy of the proposed solution with the skills that the student is expected to have acquired by the end of the course; appropriate use of language.
In evaluating the exam, the final grade considers the following elements:
1. Reasoning ability;
2. Clarity and completeness in the oral presentation of the program content;
3. Ability in writing and balancing chemical reactions and in solving analytical problems;
4. Ability to critically evaluate the results of experimental procedures;
5. Ability to make connections.
To achieve a score of 30/30 cum laude, the student must demonstrate excellent knowledge of all topics covered during the course, but most importantly, must be able to integrate them logically and coherently.
Lesson mode
The course is conducted through traditional teaching methods. Frontal teaching not only aims to provide basic knowledge in the field of analytical chemistry but also includes the ability to apply the provided knowledge to the study of both theoretical and practical reactions. These latter objectives are achieved through the completion of exercises, the explanation of educational case studies, and laboratory activities. Laboratory exercises also aim to visualize and apply the concepts learned.
