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

Mod. 1 -Theory

1) atoms

2) molecules

3) transformations of substances

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).

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.

Mod. 2 - Laboratory

- General rules of safety and behavior in the chemical laboratory.

- Experiences: (i) molecular models: from the crude formula to the molecular structure, (ii) chemical reactions of precipitation, redox, and reducing power scale, (iii) batteries and determination of equilibrium constants by electrochemical measurements.

The teacher will make the teaching material necessary to carry out the experiences (laboratory handouts and presentations) available.

The student will have to produce a written report for each practical laboratory exercise which will then be evaluated using a judgment (insufficient, sufficient, good). For module 2, there is no final exam; however, it will be necessary to obtain a positive evaluation of at least 75% of the reports to pass module 2.

 

Readings/Bibliography

I. Bertini, C. Luchinat, F. Mani, Chimica, C.E.A., Milano, 2015.

Further reading:

A. M. Shaw Astrochemistry Wiley 2006

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

Teaching methods

The course is organized in classroom lectures with the use of powerpoint. Other classroom activities (problem solving) and a few laboratory experiments 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 assessment will be based on a written examination - open questions - lasting 2 hours. The written test will be followed by a discussion of the outcome.

Teaching tools

The slides used in the lectures can be downloaded from the Internet (Virtuale Learning Environment).

Links to further information

https://www.unibo.it/sitoweb/simone.dagostino2/didattica

Office hours

See the website of Simone D'Agostino