27542 - Analytical Chemistry 1

Learning outcomes

At the end of the course, the student knows the principles of an analytical sequence; the main sampling techniques and sample treatments for solids, liquids, and gases; as well as the main analytical methods, i.e. gravimetry, acid-base titrations, spectrophotometry, and chromatography.

Course contents

Prerequisites:

No particular previous notions are required, with the exception of knowledge of arithmetic, the basics of general chemistry and stoichiometry and, for students whose mother tongue is not Italian, knowledge of Italian at level C1 or higher.

Modules 1 and 2 are required in e-learning mode [https://www.unibo.it/it/servizi-e-opportunita/salute-e-assistenza/salute-e-sicurezza/sicurezza-e-salute-nei-luoghi-di-studio-e-tirocinio] and participation in Module 3 of specific training on safety and health in the workplace. Information on the dates and methods of attendance of Module 3 can be found in the appropriate section of the course website.

Program:

The course is divided between lectures and stoichiometry exercises in the classroom, and practical experiences in the laboratory, in order to teach the student the fundamentals of the chemical-analytical method on a safe basis of calculation and manual skills.

a) Classroom exercises (24 hours - 2 CFU).

Numerical problems of analytical chemistry are solved, particularly of stoichiometry of solutions, which require the application of the concepts of mole, equivalent, concentration and dilution. The development is individual, the discussion and correction are collective.

b) Lectures (24 hours - 3 CFU).

Definition of analytical chemistry. Phases of the chemical analysis procedure. Outline of statistics: mean, standard deviation, correlation coefficient, significant figures. Quantification methods: calibration lines, internal standard, standard additions, internal normalization. Classical analysis methods. Sampling: water, air, soil. Sample storage. Probes for in situ analysis. On-site/on-line analysis of air and water. Sample preparation: grinding, drying, filtration, concentration. Use of the analytical balance. Weighing and related errors. Sample digestion (wet, microwave, Kjeldahl). Solid-liquid extraction. Steam extraction. Soxhlet extraction. Accelerated Solvent Extraction. Ultrasonic extraction. Extraction with supercritical fluids. Percolation. Liquid-liquid extraction (theory, pH effect, use of chelators, continuous extractors with solvents thicker/less dense than water, Likens-Nickerson extractor).

Chemical equilibrium. Systematic treatment of balance. Acid-base balances. Breakdown balance between phases: application to breakdown chromatography. Outline of UV-Vis spectroscopy: theory, transmittance, absorption, Lambert-Beer law. Limits of application of the Lambert-Beer law. Schematic of a spectrophotometer.

c) Laboratory experiences (16 hours 1 CFU).

The student implements in the laboratory 4 simple chemical analyses applied to real problems useful for putting into practice the notions learned in class and during the exercises. Familiarize yourself with being in the laboratory and handling simple equipment. The experiences are explained in the classroom, accompanied if necessary by calculation examples. The basics of writing a scientific report are taught, with examples. Each experience is related in writing and individually by each student. Participation in the 4 laboratory experiences is mandatory for admission to the exam. The experiences are considered concluded, valid for obtaining the requirements for admission to the exam, upon delivery of the report.

Readings/Bibliography

Daniel C. Harris, CHIMICA ANALITICA QUANTITATIVA, III Ed., Zanichelli, 2017. (*)

I. Bertini, C. Luchinat, F. Mani STECHIOMETRIA. UN AVVIO ALLO STUDIO DELLA CHIMICA, V Ed., Casa Editrice Ambrosiana (distribuzione esclusiva Zanichelli), 2009. (*)

M. Grotti, F. Ardini, Il Laboratorio di Chimica Analitica - Concetti di base ed esercizi svolti, EdiSES Napoli, 2022. (*)

R. Cozzi, P. Protti, T. Ruaro, ELEMENTI DI ANALISI CHIMICA STRUMENTALE, II Ed., Zanichelli, 2013. (^)

APAT, Manuale per le Indagini Ambientali nei Siti Contaminati, APAT Manuali e Linee Guida 43, 2006 (disponibile in rete). (^)

(*) Necessary: it contains all the parts (and much more) that must be studied in order to pass the exam.

(^) Not necessary to pass the exam: useful for further study, even in the future.

Teaching methods

The course consists of 24 hours of classroom exercises, 24 hours of lectures and 16 hours of laboratory experiences. During the exercises, numerical stoichiometry exercises are done. During the lessons, the various steps of the analytical procedure are explained. During the laboratory experiences, students apply analytical techniques studied in class and calculations practiced during the exercises. In general, the stoichiometry exercises in the classroom occupy the first part of the course; This is followed by lectures and, in May, laboratory experiences.

The teaching tools are the blackboard, Excel and PowerPoint.

The teaching source is the textbooks recommended above and the material presented in the classroom and/or deposited on Virtuale.

The topics of the lessons and any other material discussed in the classroom or considered useful for study and in-depth study are uploaded to Virtuale (the Unibo repository) after the individual lessons or exercises. Regular consultation is recommended.

Assessment methods

Students with learning disorders and\or temporary or permanent disabilities: please, contact the office responsible (https://site.unibo.it/studenti-con-disabilita-e-dsa/en/for-students ) as soon as possible so that they can propose acceptable adjustments. The request for adaptation must be submitted in advance (15 days before the exam date) to the lecturer, who will assess the appropriateness of the adjustments, taking into account the teaching objectives.

The exam is carried out in written form on EOL, in presence, in the computer room, on a PC made available by Unibo. The consultation of texts, notes, internet and fellow students is not authorized. The student can type directly on EOL, or can write in excellent handwriting on their own sheet of paper that they scan and attach to EOL as a pdf. Messy or difficult to read papers will NOT be evaluated. Familiarization with the platform and the PC is left to the student's initiative. If the calendar and availability of the computer room allow it, an exam will be carried out as a familiarization test without evaluation.

Exam duration: 90 minutes.

View the opening and closing date of registrations on Almaesami - it is not possible to register after the deadline.

Admission to the exam.

Attendance at the workshop is mandatory. To be admitted to the final exam, the student must:

a. have carried out all the laboratory exercises, arriving on time, observing the rules of good behaviour and following the instructions given by the teacher and assistants in the laboratory;

b. have delivered all the reports of the experiences within the assigned deadlines (normally to the next experience, unless otherwise assigned).

Students who do not comply with the above obligations are not admitted to the exam.

Exams.

The exams consist of a written test to be carried out on the Unibo EOL platform containing 4 exercises: the first two (part A) concern more specifically stoichiometry while the third and fourth exercises (part B) concern laboratory experiences and the topics presented in class.

The first exercise consists of calculating the concentrations of 5 solutions at the end of a certain dilution, expressing each result in two units of measurement. Each correct answer is worth 3 points. If one answer in one unit of measurement is correct while the other is wrong or not given, the student gets 1 point. The wrong or not given answer in both units of measurement gets zero points. The maximum score for this exercise is 15 points, which are converted to a maximum of 10.

The second exercise is a typical stoichiometry problem, following the example of those reported in the texts recommended above. The maximum score for this exercise is 5 points. The wrong answer or not given gets zero points.

Part A of the exam therefore has 15 points available and is considered sufficient with at least 9 points.

The third exercise consists in the use of the Excel sheet for the calculation of the analyte concentration of an unknown sample analyzed with an instrumental method, with the method of the external standard, added standard or internal standard, similar to what the student put into practice to report on laboratory experience number 4. For this exercise the maximum score is 7.5 points. Errors in the calibration line, in the unit of measurement, in the concentration, in the calculation of dilution, in the analyte lead to evaluation with zero points.

Finally, the last exercise consists of one or two open-ended questions on the topics covered in class. Maximum score 7.5 points. The evaluation of this exercise can be interpreted as follows: 4.5-5.9 points (sufficient: barely adequate knowledge of the topic, some even serious errors); 6-6.9 points (good: more than satisfactory knowledge of the topic, some non-serious errors); 7-7.4 points (very good: practically exhaustive knowledge of the topic, some imperfections or expository defects); 7.5 points (excellent: impeccable, exhaustive knowledge of the subject, free of even minimal errors, clear and technically impeccable exposition).

Part B of the exam therefore has 15 points available and is considered sufficient with at least 9 points.

The student passes the exam when the grade is sufficient (at least 9 points) in both tests.

To reward the student for the effort made in writing the reports of the experiences, the final grade is given by the sum of the scores of parts A and B (maximum 30) expressed in thirty-first.

The sufficient grade can be rejected only once.

Final evaluation.

The final evaluation can be interpreted as follows.

Points 18-23: sufficient knowledge of the subject, some serious errors;

Points 24-26: good knowledge of the subject, few minor errors;

Points 27-29: very good knowledge of the subject, some imperfections, some presentation defects;

Points 30-31: excellent knowledge of the subject, impeccable, exhaustive and clear exposition, absent even the slightest imperfections; Honors are awarded when these qualities stand out as rare, far above the average of the hundreds of students examined.

At the discretion of the teacher, the student who obtains 31 points can receive the grade of 30 laude.

Once the correction of the assignments has been completed, the exam grade is published on Almaesami and the papers, with any corrections, observations of the teacher and scores of the individual parts of the test, are made visible on EOL until the grade is recorded. Students are informed immediately with a notification from Almaesami and must immediately notify the teacher by e-mail if they intend to refuse the passing grade, an option that can be exercised only once. Normally, the vote is registered within three days.

For all matters not provided for in this chapter, the University teaching regulations apply.

Teaching tools

Blackboard, PowerPoint presentations (et similia), chemical laboratory equipment.

Teaching material published on Insegnamenti virtuale.unibo.it. Regularly consult the lesson spaces, announcements and emails.

Attention: the teaching material above is NOT intended to replace the textbooks nor sufficient (on its own) to pass the exam with profit.

The actual teaching material of the course are to be considered the recommended textbooks.

Office hours

See the website of Guido Galletti