00088 - Chemistry

Learning outcomes

The objective of the course is to provide the essential elements relative to the composition and behaviour of the various substances that constitute the Universe. At the same time, the course is intended to give the necessary information for a critical analysis on the following topics:

- the composition of the material objects in the surrounding world;

- the dependence of the macroscopic properties of substances on their microscopic composition and structure;

- the ability of substances to combine together, or to decompose, giving rise to other substances.

Course contents

The course is divided in three parts, corresponding to the following subjects:

1) characterization of the fundamental components of substances (atoms);

2) study of the chemical properties of atoms, i.e., of their ability to aggregate according to well established rules, giving rise to a huge variety of substances (chemical species);

3) study of the transformations of substances, either spontaneous or man-made, and of the conditions in which these transformations can take place (chemical reactions).

 

PART I: macroscopic and microscopic structure of matter

The atomic structure of matter. Atoms. Chemical formulas and molecular weight. Mole. Qualitative and quantitative meaning of chemical formulas.

The electronic structure of atoms. Bohr's atomic model. Quantization of energy. Dual nature of the electron and Heisenberg's principle. Wave theory, quantum numbers and atomic orbitals. Energy levels for atomic hydrogen. Atomic orbitals in atoms with many electrons. Pauli's principle and Hund's rule. Electronic configuration of atoms (aufbau) and periodic classification of chemical elements (Periodic Table). Laboratory experiment on atomic spectroscopy.

Periodic change of the physical properties of atoms. Atomic size, ionization energy and electron affinity.

 

PART II: the chemical bond

The chemical bondand the energy of the system. Bond energy. Classification of chemical bonds.

The covalent bond. Valence bond theory. Polarity of covalent bonds, electronegativity. Stoichiometry of covalent compounds. Molecular geometry and VSEPR model. Polar and apolar molecules. Laboratory exercise on molecular geometry and polarity. Molecular orbital theory. Energy diagram of the molecular orbitals and electronic configuration of some simple biatomic molecules.

The chemical bond in the solid state. Ionic bond. Structure and properties of ionic compounds. Metallic bond. Short account on band theory for solids. Conductors, insulators and semiconductors.

Attractive forces between molecules in condensed phases. Van der Waals interactions. Hydrogen bonds. Factors determining the aggregation state of a substance.

Periodic behaviour of bond properties. Relationship between bond types and atom position in the Periodic Table. Prediction of the bond nature.

Chemical properties of the elements relative to their position in the Periodic Table. Periodic chemical properties. Properties of the compounds between the various elements and oxygen (oxides, hydroxides, oxoacids) or hydrogen (hydrides). Salts. Solutions: properties and composition. Gaseous solutions. Solubility. Electrolytic solutions.

 

PART III. Chemical reactions

Chemical equations. Energy involved in chemical reactions: internal energy and entalpy. Spontaneity of a chemical process: entropy and free energy.

Chemical equilibria. Homogeneous and heterogeneous equilibria. Equilibrium constant and its temperature dependence. Predictions on the evolution of a chemical system. Principle of Le Chatelier. Choice of the best reaction conditions.

Chemical kinetics. Rate of a chemical reaction. Factors affecting the reaction rate. Rate constants, order of reactions and lifetimes. Reaction mechanism and elementary steps. Activation energy. Catalysis.

Thermodynamic and kinetic aspects of a reactive chemical system. Laboratory experiments on the reactivity of some chemical species.

LABORATORY ACTIVITIES

 

- General safety rules and correct behaviour in the chemical laboratory

- Description of the main glassware components and accessories used in the laboratory

- Experiment 1: atomic spectroscopy

- Experiment 2: flame tests

- Experiment 3: study of molecular geometry with physical models

- Experiment 4: redox reactions

- Experiment 5: precipitation, displacement, and complexation reactions

Readings/Bibliography

Textbooks:

 A. M. Manotti Lanfredi, A. Tiripicchio, Fondamenti di Chimica, C.E.A, Milano, 2006.

I. Bertini, C. Luchinat, F. Mani, Chimica, C.E.A., Milano, 2004.

L. Moggi, M. Venturi, Chimica Generale ed Inorganica (2° ed.), Corso Ed., Ferrara, 2002.

 

Further reading:

M. Munowitz, Chimica, Zanichelli, Bologna, 2003

P. Chiorboli, Fondamenti di Chimica, UTET, Bologna

P. Atkins, L. Jones, Chimica Generale, Zanichelli, Bologna, 1998

Teaching methods

The course is composed mainly of classroom lectures with the use of transparencies. Other classroom activities (problem solving) and a few laboratory experiments (8 hours of overall activity in the lab) are carried out. Subjects of high impact (e.g., under an applicative point of view), related to the topics treated in the course, are presented if time is available.

Assessment methods

The learning assessment takes place with the final exam. The acquisition of the learning outcomes is ascertained by means of a written test of 3 hours, to be undertaken without the support of notes or textbooks, followed by an oral exam. The preparation of a written report for each laboratory experiment is also required.

The written test consists of 5 questions and/or numerical problems, each related to a different topic of the program (atomic weight and mole, atomic structure, periodic properties, chemical bond, Lewis stucture formulas and molecular geometry, intermolecular forces, reaction stoichiometry, thermodynamics; chemical kinetics is not included in the topics for the test).

The written exam is not given a mark; if positive, the student is admitted to the oral exam. The written test is passed if 3 out of 5 problems are correctly solved. In the case of test that are not full sufficient but very close to the previously mentioned threshold, admission to the oral exam “with a reservation” can be made. The admission to the oral exam is valid for one solar year since the date of the positively evaluated written test; during this period the student can take the oral exam in any available session.

The oral exam has an average duration of 30 minutes and consists of at least 3 questions on the various topics of the course. If the oral exam is failed the written test, if passed with full sufficiency, does not have to be repeated; the student can try the oral exam again in a later session, within the term of validity of the written test. If, conversely, the admission to the oral test was obtained “with a reservation”, the failure of the oral exam cancels the result of the written test, which therefore has to be taken again.

The laboratory reports are not given a mark. If, however, the student does not participates to the laboratory activities without appropriate justification and/or he/she does not delivers the reports, the final mark of the exam is lowered by 2 points (2/30) or, in case of a very positive result, the honor is not assigned.

The final mark is determined at the end of the oral exam.

Teaching tools

The transparencies used in the lectures can be downloaded from the Internet (UniBo > Alberto Credi > Insegnamenti > Chimica > Materiale didattico). The text of problems and exercises – some with solution – for training to the written test are available in the same site.

Links to further information

http://www.photonanolab.it

Office hours

See the website of Alberto Credi