60/58/157 - ANALYTICAL CHEMISTRY I AND LABORATORY
Academic Year 2021/2022
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DAVIDE ATZEI (Tit.)
- Teaching style
- Lingua Insegnamento
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The educational objectives of the Analytical Chemistry I and Laboratory course can be declined according to the Dublin Descriptors according to the following scheme:
Applied knowledge and understanding: the student will acquire knowledge on the fundamentals of analytical chemistry and the principles of the classical methods of quantitative analysis; The student will be able to solve analytical problems related to the equilibria in solution (acid-base equilibria, precipitation, complexation and oxidation-reduction equilibria). The students will also develop laboratory skills improving their confidence with laboratory equipment and chemicals manipulation. They will also be able to appropriately present and evaluate analysis results.
Making judgements: the student will be able to identify the most appropriate technique and method of volumetric analysis to respond to a specific analytical problem. The students shall develop a critical attitude, necessary to correctly evaluate the results of a volumetric analysis, and the ability to identify critical parameters in order to develop a method of analysis.
Communication skills: the student will be able to effectively communicate their knowledge, discuss their ideas and defend their conclusions using the appropriate analytical chemistry technical language, to both expert and non-specialist interlocutors.
Learning skills: At the end of this course, the student will possess a study methodology that will allow him to easily learn new topics; He will be able to access and use the bibliographic sources for professional development independently and appropriately (bibliography, databases, European regulations and Italian laws).
The course is recommended to students who have passed the General Chemistry and Lab courses exams.
The course is recommended to students who have passed the General Chemistry and Lab courses exams.
Introduction: basic tools of Analytical Chemistry, the language of Analytical Chemistry. Kind of errors: accuracy and precision. How calculate the mean and median, standard deviation, absolute and relative error; propagation of uncertainty.
The solvents. Aqueous solutions. Equilibrium constants. Ionic strength, activity and activity coefficient, thermodynamic and stoichiometric constants.
Separative techniques; thin layer chromatography, notes on gas chromatography and HPLC.
Acid-base equilibria: acid and base definitions. The role of the solvent. Acid and base strength.
The pH scale: strong acids and bases, weak acids and bases. Buffers and polyprotic acid-base systems.
Titrimetric methods of analysis. Acid-base titration curves and common errors in titrations. Fractional composition diagrams: evaluation.
Equilibrium in complex formation. Coordination processes. Ligands and their properties. The formation constant and the conditional formation constant. Complexometric EDTA titration curves. Metallochromic indicators.
Titration based on redox reactions. Redox processes and influence of pH, solubility, ionic strength and coordination processes. Quantitative applications and evaluation of redox titrimetry.
Precipitation equilibrium. The solubility of ionic compounds. Solubility product: the common ion effect, pH effect, ionic strength effect and the effect of coordination processes. Titration curves, common errors in precipitation titrations.
Gravimetric methods of analysis. Overview; how to perform a gravimetric analysis. Filtration, drying and determination of the mass. Methods to obtain high quality precipitates. Example of gravimetric analysis.
Safety and behavior in laboratory.
Chemicals: classification, manipulation rules, toxicity and disposal.
Laboratory techniques related to the more common practices required by quantitative analysis; proper use of buret and pipet. Balances, weighing and weighing errors.
Glassware: classification, use, calibration, washing
Laboratory notebook and its correct drafting.
Fundamental Units of measure. Units for expressing concentration. Molarity; weight, volume, and weight-to-volume ratios. Converting between concentration units.
Primary and secondary reagents.
Buffer solutions: pH and mechanism of action.
Titrimetric methods of analysis.
Indicators and their use. Titrating acids and bases. Selection of indicators in terms of strength and concentration of reagents. Precipitation titrations and indicators; titrations based on complexation reactions and metallochromic indicators; titrations based on redox reactions and redox indicators.
Numerical exercises and discussion of the results obtained in the laboratory
Determination of the concentration of a solution of strong acid by yhe use of Na2CO3
Strong acid-strong base Titration
Weak acid-strong base titrtion and graphical representation of the titration curve, choose of the indicator
Determination of the concentration of a solution of AgNO3 by the use of NaCl
Determination of the concentration of Cl- (Mohr method).
Determination of the concentration of a solution of KSCN.
Titration of a containing Cl- solution (Volhard method).
Titration of a EDTA solution by ZnO
Determination of the unknown concentration of calcium and magnesium.
Theoretical lectures and calculation exercises (56 hours).
Based on the context conditions related to the Covid-19 pandemic, the teaching will be delivered at the same time both in presence and online. Each student, at the beginning of the semester, can choose between the teaching in presence or distance. Depending on the availability of the classrooms and the number of students choosing for in the presence teaching, there may still be a shift for the actual access to the classroom.
Laboratory exercise and individual laboratory work (72 hours).
Based one the Covid-19 pandemic evolution, laboratory shifts and/or on line activities might be programmed.
Verification of learning
The final exam is unique for both modules. The students have to present the Laboratory notebook before the exam and they can choose to sustain a practical laboratory test (optional) for more point at the end of the course. During the lab. test, the student shall replicate one of the experiments carried out during the course. The exam consists of a written exam (the student will solve practical analytical chem. problems on the topics covered during the course) followed by an oral exam (the student will be asked to illustrate the theoretical principles of the topics covered in the course).
The mark, one for both modules, will be calculated as follow: written assignment (25%); practical test, laboratory notebook and laboratory behaviour (25%); oral interview (50%).
Due to the Covid-19 pandemic the aforementioned exam may be replaced by a remote interview (on the MS Teams platform). The first part of the test will consist in the resolution of an analytical chem. problem similar to the ones discussed in class course. The resolution of the exercise is mandatory to access to the actual interview. The first questioning topic will be chosen by the student and it will be followed by other questions chosen by the commission that can cover all the topics of the course.
The score that refers to the final exam takes into account the following factors:
* Quality of knowledge, skills, competences possessed and/or manifested:
appropriateness, correctness and congruence of knowledge, skills and competences
* Exhibition mode:
- Expressive ability;
- Appropriate use of the specific language of the discipline;
- Logical and consequential skills in the connection of the contents;
- Ability to connect different topics by finding common points and establish a coherent general design, i.e. taking care of the structure, organization and logical connections of the exhibition discourse;
- Ability to synthesize also through the use of the symbolism proper to matter and the graphic expression of notions and concepts, in the form for example of formulas, reactions, schemes, graphs and equations.
* Relational qualities:
Availability for exchange and interaction with the teacher during the interview.
* Personal qualities:
- critical spirit;
- capacity for self-assessment.
The score of the exam is assigned in thirtieths on the basis of the following learning assessment scale.
Every point of the exercise is correct and each step to reach the final solution is fully described; the most appropriate resolution methods have been used. The oral presentation is content-rich, precise and involves personal thoughts; the language use is correct and the knowledge is highly appropriate in every detail.
The student organizes its answer optimally doing, when possible, a comparison between the different analitycal methods.
The procedure for the solution of the exercise is formally correct but the best solution methods have not been used. The oral presentation is clear and fluent; the language use is adequate and the knowledge is good but not particularly detailed.
The procedure for the solution of the exercise contains some easy to find careless mistakes (wrong symbols or constants). The oral presentation is clear but the student often hesitates or repeats himself. The use of language looks poor but, despite some uncertainty, the knowledge is adequate.
The procedure for the solution of the exercise shows significant errors but it was started and set correctly. The oral presentation is unclear; the language use is poor and the knowledge is barely sufficient. The student is not capable to compare different methods (when possible) while answering the question.
Serious mistakes in concepts or in the procedure. The exercise or the question is not understood.
a) Chimica Analitica e Analisi Quantitativa ; Davide Hage e James Carr, Ed Piccin; capitoli 1- 13
b) Chimica Analitica , Una Introduzione ; Skoog, West, Holler, Ed SES
c) Chimica Analitica Quantitativa; Daniel Harris, Ed Zanichelli
d) Esercizi per la Chimica Analitica; Silvia Araneo, Ed Soc. Editrice Esculapio.
The lessons are available as .pdf file; feel free to ask the professor for them. A Dropbox link containing all the lessons will be given to the students at the beginning of the course.