66684 - Analytical Chemistry and Laboratory

Learning outcomes

At the end of the course the student is able to understand and apply the analytical techniques, can identify the chemical equilibria present and evaluate. Influence of chemical parameters on them. He knows the basic statistics necessary for the presentation of analytical data. He knows the potentiometric analytical techniques. At the end of the course, students will be able to recognize the laboratory equipment and describe its use; know how to implement key techniques of volumetric analysis for the quantitative determination of chemical species on the basis of chemical equilibria involved. Will be able to bear with the work of a lab notebook. It will also be able to process and present experimental results using the most appropriate statistical tests.

Course contents

THEORY:

Fundamentals of statistics in analytical chemistry: Quality of analytical data. Significant figures. Sources of uncertainty. Errors in chemical analysis. Gross, systematic and random errors. Accuracy and precision. Propagation of errors. Methods for reporting analytical data. Significance tests: Student's t. Test for evaluating accuracy. Test for evaluating precision. Comparison of two experimental means. Calibration and measurement. Linear regression. Concept of detection limit.

Acids and bases in water: Strength of acids and bases. Polyfunctional acids and bases. Ampholytes. Buffer solutions. Systematic approach to the chemical equilibria. pH calculations. Acid-base titrations methods for estimating thre equivalent point. Titration error. An outline on acids and bases in non aqueous solvents. Acid/base properties of solvents. Influence of solvents in acid/base reactions.

Solubility equilibria: Solubility as a function of pH. Precipitation titrations.

Complex formation: Complexation as a function of pH. Conditional and thermodynamic constants. Solubility as a function of complexation. Complexometric titrations. EDTA and analytical applications. Interferences and masking.

Redox equilibria in homogeneous phase: Electrochemical cells. Influence of pH, solubility and complex formation on redox potential. Stability of redox systems in water. E/pH diagrams. Redox titrations.

Potenziometry: Direct and indirect measurements. Indicator and reference electrodes. Ion selective electrodes. Potentiometric titrations.

Conductimetry: Direct and indirect measurements. Conductometric titrations.

LABORATORY:

The following experiments will be performed in the laboratory:

1. Calibration of buret, pipet and volumetric flask by weight of water delivered.
2. Titrimetric determinations: Neutralization methods.
3. Complexation titrations.
4. Redox titrations.
5. Potentiometry. Glass electrode: Calibration, calibration curve (E-pH), and tritimetric determination of an acid  using Gran's plot. Analytical determination by using ion sensitive elecytrodes.
6. Potentiometric
7. Conductivity. Evaluation of the cell constant. Titrations.

Readings/Bibliography

D.C. Harris, “Chimica Analitica Quantitativa”, Zanichelli, Bologna,

F. W. Fifield, D. Kealey, “Chimica Analitica teoria e pratica”, Zanichelli, Bologna

Skoog,. West, Holler,Crouch, “Fondamenti di Chimica Analitica”, EdiSES, Napoli

Elizabeth Prichard, Victoria Barwick, "Quality Assurance in Analytical Chemistry" John Wiley

C. G. Enke, “The art and science of chemical analysis”Wiley

Teaching methods

The course of analytical chemistry and laboratory involves front lecture (theory and introduction notes for the laboratory experiences), numerical calculation on solution chemistry and laboratory experiences. Students should have a bound laboratory notebook for recording all the data at the time of the observation during laboratory classes. The recording of data on loose pieces of paper or in a preliminary note book is expressly forbidden.

Assessment methods

The exams are designed to assess the achievement of the following learning objectives: (i) principles and chemical analysis procedures and the planning of a simple analytical process;(ii) ability to express the results of a quantitative analytical procedure; (iii) principles of the main chromatographic, electrochemical and spectroscopic techniques.

The exam is done through the specific written tests and / or a final exam. The final evaluation will be done simultaneously with the Instrumental Chemical Analysis course.
The written non-structured tests consist of solving several problems.
The first part will focus on statistics and the second test will cover the following topics: Acids and bases equilibria, Solubility equilibria, Complex formation, Redox equilibria, Potenziometry and Conductimetry.

If the ongoing tests will be not sufficient the respective topics, will be the subject of a final written test, which will consist of solving problems and answering questions aimed at evaluating the understanding of the respective topics.

The written tests provide for a maximum score of 33/30 with the assignment of points to the individual exercises communicated at the beginning of the test.

For the tests it will be possible to use: periodic table of the elements, calculator and the necessary for the realization of simple graphs (ruler, graph paper).

The first ongoing test (if sufficient) contributes to 20% of the final score while the second to 50%. The final mark is completed with that of the Instrumental Analytical Chemistry course which will be worth the remaining 30%.

The evaluation of the lab course will be based:

Student behaviour (compliance with accident prevention regulations, use of PPE, proper use of glassware and small instruments), +/- 0.75 to mediate with Lab of Analytical Chemistry Instrumental
results of one or more analysis, +0.5 to test if the result has an error less than 3%
laboratory notebook, +/- 0.75

The evaluation, integrated with laboratory of the Instrumental Analytical Chemistry is added to the evaluation of the theory.

The evaluation process may be modified due to emergency covid19.

Teaching tools

Use of the projector and blackboard during classes. Textbook.

Office hours

See the website of Erika Scavetta

See the website of Isacco Gualandi