66684 - Analytical Chemistry and Laboratory

Learning outcomes

At the end of the course the student is able to understand the principles defining analytical chemistry from the point of view of the "problem solving" approach. Furthermore, he has acquired knowledge as to: chemical equilibria in solution with particular attention to the simultaneous ones with the aim of carrying out simple qualitative tests and of defining the optimal conditions for a reaction to occur; volumetric and gravimetric quantitative determinations; standard analysis procedures, understanding and development of a SOP; statistical treatment of the data and significance tests for the final evaluation of analytical data; potentiometry and its applications.
Moreover the student is able to draw up an analysis certificate.

Course contents

Prerequisites

-Atomic structure- Atomic mass- Chemical forces and bonds- Molecules- Molecular, covalent, metallic and ionic solids- Molecular mass- Mol- Chemical reactions and conservation of mass- Elemental analysis- Nomenclature

- Homogeneous chemical equilibrium- Definitions of concentration- Equilibrium constants and their use- Heterogeneous equilibrium- The le Chatelier principle

-Electrochemistry: Chemical energy and electrical work- Electrochemical cells- Standard potentials- Latimer diagrams- Nernst equation

 

 

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.

LABORATORY COURSE

Frontal lessons

Tracking laboratory activity. The volumetric glassware: characteristics, use, calibration. Practical features of volumetric titrations: determination of endpoint by means of indicators or graphical and numerical methods. Primary standards. Error treatment. Introduction to potentiometry

Lab activity

Preparation of solutions.   Acid-base titrations: standardisation of HCl and NaOH solutions; determination of the titer of the titer of unknown solutions. Redox and complexometric titrations: determination of the titer of unknown solutions.  Potentiometric titrations.

Numerical exercises

Besides the laboratory experiments the  students will have to conduct the statistical treatment of the experimental data obtained during their Lab activity.The students have to compile their own laboratory notebook, recording their activity and results. The laboratory notebook will be used for course evaluation and credit.

Readings/Bibliography

D.A. Skoog, D.M. West, F.J. Holler, S.R. Crouch, Fondamenti di Chimica Analitica. EdiSES, Napoli, 2005.

D.C. Harris, Chimica Analitica Quantitativa, Zanichelli, Bologna, 2005.

Teaching methods

Lectures integrated by exercises related to the discussed topics. It is encouraged individual study on text books and team-discussion on the arguments under study. The Course is integrated with that of laboratory work. Theory and laboratory work must co-exist since practice not only develops the capability of the student to think but also to act independently.

Assessment methods

The assessment of learning takes place through a final written exam.The score is integrated with that obtained for the Laboratory of Analytical Chemistry course (only one final mark). The written examination aims to verify the acquisition of the learning outcomes expected from the knowledge of the topics which constitute the programs of both Courses.

Teaching tools

Lectures and class-room activities are carried out with the help of video-projection. Laboratories, software for data treatment, experiences booklet.

The teaching material is available to the students. The experimental work will be carried out in the Analytical Laboratory.

Office hours

See the website of Erika Scavetta