Course Summary

CHM101 - Basic Concepts

The course described here is based on one of the first 18 hour lecture courses (or module) given to first year chemistry undergraduates at the University of Sheffield in England. The course is targeted at level one (first year), single and dual honours chemistry and chemical physics students, with the aim of giving a universal foundation into some basic physical chemistry.

The course covers a multitude of topics summarised in the table below. It covers some of the basic Physical Chemistry which may have been seen at earlier educational levels. This includes for example the concepts of enthalpy and entropy which will be expanded upon and given more precise definitions.

Dr Barry Pickup and Dr Neil Bailey of the department provided their lecturer's notes which forms the basis of the text. Assistance and pointers were provided by Neal Berridge and Dr Mark Winter, the computer resource manager of the department. The chemistry department has an extensive well used site that is a positive gold mine to visit and a link is provided to it.

B.T.Pickup@shef.ac.uk

N.A.Bailey@shef.ac.uk

J.A.HALL@shef.ac.uk

M.J.Winter@shef.ac.uk

Table of Contents

Subject Area Summary of contents
Introduction Introduction to the problems of preconceptions and misconceptions, a cautionary tale. Theories and models in chemistry. Atoms and their constitution; the fundamental particles; isotopes.
Additional Comments.
The Beginning. The cosmic distribution of the elements. The origin of the elements: the Big Bang theory: Hydrogen burning, Helium burning, Carbon burning and Oxygen burning, super-novae and slow neutron capture.
Spectrums and electron. The electromagnetic spectrum- probabilities, wavelength, frequency and wave-numbers. Quantization of energy and Planck's constant. The solar spectrum; the hydrogen absorption spectrum: emission spectra. Lyman, Balmer and Paschen series of lines: the Rydberg constant. The Bohr atom. Developments of the Bohr atom by de Broglie and Schrodinger: electron distributions as probabilities.
Tutorial question and Answer 1. A problem posed by Dr Bailey.
Quantum Number descriptions of orbitals. Quantum numbers - 'principal' (n), 'angular momentum' (l) and 'magnetic' (m) - their numerical values. Angular and radial properties of the orbitals defined by quantum numbers. The radial distribution function. S P and D orbitals.
Electron filling of Orbitals. Orbital occupancy - the Pauli exclusion principle. Hund's maximum multiplicity rule and the build up (aufbau) of electron configurations. Variation of atomic radius down Group 1 and across the first main period. Ionisation energy.
Bonding and Electronegativity. Bonding. Types of bonding - ionic (octet rule); covalent (Lewis "dot-and-cross representation); polar bonds. co-ordinate (dative, donor-acceptor Electronegativity - definition and Pauling's scale.
Bonding and Electronegativity 2. Bonding BF₃ and NH₃ . Dipoles. Oxidation State. Multiple Bonds 0₂ and N₂ Valence shell electron pair repulsion.
Molecular Orbital Discussion. Simplification of the Schrodinger equation Dihydrogen MO's.
Molecular Orbital Discussion. Fluorine MO. Dinitrogen MO.
Tutorial Questions and answers 2. A further problem posed by Dr Bailey.
Molecular Energies. Energy defined. Work and Force Heat. Kinetic and Potential Energy. Conservation of Energy. Dimensional Analysis.
Work and Heat: The First Law of Thermodynamics. Internal Energy Work done on expansion of a gas. Heat. The First Law of Thermodynamics
Enthalpy and Thermochemistry. Standard Temperature and Pressure. Exothermic and Endothermic processes. Standard states and Standard enthalpy changes leading into Hess's Law
The Boltzmann Distribution - Internal energy modes. Translational, Rotational and Vibrational degrees of freedom The exponential function explained and illustrated. The Boltzmann Distribution.
Acid and Base equilibria. Bronsted acids and bases. Bronsted acid-base equilibria. Autoionisation. Strong acids, pH and ionisation constants. Acid strength and structure.
Acid and Base continued. The pH of weak acids and bases. Polyprotic acids and bases. Buffer solutions - the Henderson Hasselbach equation. Calculating the pH of a buffer solution. Acids, Bases and Salts.
Tutorial Questions 3. Questions set by Dr Pickup.
Tutorial Answers 3 (1-8). Answers to Dr Pickups questions.
Tutorial Answers 3 (9-15). Answers to Dr Pickups questions.
Appendix 1. Glossary of highlighted terms.
Appendix 2. Units and Dimensions Table. Moles and Molar Quantities. System International.

Subject Area	Summary of contents
Introduction	Introduction to the problems of preconceptions and misconceptions, a cautionary tale. Theories and models in chemistry. Atoms and their constitution; the fundamental particles; isotopes.
Additional Comments.
The Beginning.	The cosmic distribution of the elements. The origin of the elements: the Big Bang theory: Hydrogen burning, Helium burning, Carbon burning and Oxygen burning, super-novae and slow neutron capture.
Spectrums and electron.	The electromagnetic spectrum- probabilities, wavelength, frequency and wave-numbers. Quantization of energy and Planck's constant. The solar spectrum; the hydrogen absorption spectrum: emission spectra. Lyman, Balmer and Paschen series of lines: the Rydberg constant. The Bohr atom. Developments of the Bohr atom by de Broglie and Schrodinger: electron distributions as probabilities.
Tutorial question and Answer 1.	A problem posed by Dr Bailey.
Quantum Number descriptions of orbitals.	Quantum numbers - 'principal' (n), 'angular momentum' (l) and 'magnetic' (m) - their numerical values. Angular and radial properties of the orbitals defined by quantum numbers. The radial distribution function. S P and D orbitals.
Electron filling of Orbitals.	Orbital occupancy - the Pauli exclusion principle. Hund's maximum multiplicity rule and the build up (aufbau) of electron configurations. Variation of atomic radius down Group 1 and across the first main period. Ionisation energy.
Bonding and Electronegativity.	Bonding. Types of bonding - ionic (octet rule); covalent (Lewis "dot-and-cross representation); polar bonds. co-ordinate (dative, donor-acceptor Electronegativity - definition and Pauling's scale.
Bonding and Electronegativity 2.	Bonding BF₃ and NH₃ . Dipoles. Oxidation State. Multiple Bonds 0₂ and N₂ Valence shell electron pair repulsion.
Molecular Orbital Discussion.	Simplification of the Schrodinger equation Dihydrogen MO's.
Molecular Orbital Discussion.	Fluorine MO. Dinitrogen MO.
Tutorial Questions and answers 2.	A further problem posed by Dr Bailey.
Molecular Energies.	Energy defined. Work and Force Heat. Kinetic and Potential Energy. Conservation of Energy. Dimensional Analysis.
Work and Heat: The First Law of Thermodynamics.	Internal Energy Work done on expansion of a gas. Heat. The First Law of Thermodynamics
Enthalpy and Thermochemistry.	Standard Temperature and Pressure. Exothermic and Endothermic processes. Standard states and Standard enthalpy changes leading into Hess's Law
The Boltzmann Distribution - Internal energy modes.	Translational, Rotational and Vibrational degrees of freedom The exponential function explained and illustrated. The Boltzmann Distribution.
Acid and Base equilibria.	Bronsted acids and bases. Bronsted acid-base equilibria. Autoionisation. Strong acids, pH and ionisation constants. Acid strength and structure.
Acid and Base continued.	The pH of weak acids and bases. Polyprotic acids and bases. Buffer solutions - the Henderson Hasselbach equation. Calculating the pH of a buffer solution. Acids, Bases and Salts.
Tutorial Questions 3.	Questions set by Dr Pickup.
Tutorial Answers 3 (1-8).	Answers to Dr Pickups questions.
Tutorial Answers 3 (9-15).	Answers to Dr Pickups questions.
Appendix 1.	Glossary of highlighted terms.
Appendix 2.	Units and Dimensions Table. Moles and Molar Quantities. System International.

Further reading for the later third section of the course can be found in the recommended undergraduate text book:

General Chemistry, 2nd Edition,

by P.W. Atkins and J.A. Beran

Publ. W.H. Freeman and Co.

The notation used in this text book will not always be used, since it is primarily of a lower educational level and in a few cases uses notation which is not quite correct. There is no calculus in the course, but it is necessary to appreciate some notation required to denote very small physical quantities - infinitessimals. A physical quantity x, can be considered to be incremented by a very small amount dx, to give a final value of x+dx. The quantity dx, is to be read not as a multiplication 'd times x', but as an infinitesimal increase to the original quantity x. The precise meaning of 'infinitessimal' requires the concept of a mathematical limit for its true appreciation. Here, we shall merely regard dx as 'an extremely small change in x'. In mathematics it would be more usual to use the notation dx , but in thermodynamics we prefer the straight 'd' notation. Another term which is used to describe these infinitesimal changes is a 'differential'.

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