Principles of Chemistry
Introduction to the Principles of Chemistry
Rena Abbasova
Baku Higher Oil School,
September 2013
Text book:
Chemistry, 2nd Edition
by Blackman, Bottle, Schmid, Mocerino and Wille
Reference to book pages on notes e.g. [T p15-20]
Modes of Learning
 Lectures
 Tutorials
 Webtests
 Workshops
 Private study
Lectures
 New concepts , new facts
 Make your own notes - Focus on the main points!
 Review your notes asap after each lectures
Your attendance is obligatory!
Tutorials
 Individual attention to the students
 More interactive and specific than a book or a
lecture
 Help develop your understanding of the subject,
not test it
Your attendance is required!
Webtests
 Relate to the lecture material
 Available via the University virtual learning
environment – VISION
 Formative not summative (This semester ONLY)
 Possibility of repeated attempts (as often as you wish)
Workshops
they help develop your understanding of the
subject, not test it!
 Problems will be given out in advance
 Self study before workshop is obligatory!
Your attendance is required!
Private study (Self-study)
You must supplement your timetabled time
with private study!
 Revising and Supplementing lectures notes
 Reading the textbook
 Researching and answering tutorial questions
To succeed in exam
you need to be strongly motivated:
 Read the textbook
 Attend lectures, tutorials and workshops and be
active
 Research and answer tutorial questions
 Work before and at the workshops
 Use webtests
 Spare no effort to private study
Schedule of course
Week
Lecture
Tutorial
Webtest
Wokshop
Private study
1
Intro, 1-3
2
2
4-6
2
3
7-10
2
4
11-13
2
2 (L6-9)
1 (L6-9)
≥ 6 hrs
5
14-16
2
3 (L10-13)
2(L10-13)
≥ 6 hrs
6
17-19
2
4 (L14-17)
3(L14-17)
≥ 6 hrs
7
20-22
2
5 (L18-21)
4(L18-21)
≥ 6 hrs
8
23-26
2
9
27-29
2
6 (L22-25)
5 (L22-25)
≥ 6 hrs
10
30-32
2
7 (L26-29)
6 (L26-29)
≥ 6 hrs
11
33-35
2
8 (L30-33)
7(L30-33)
≥ 6 hrs
12
36, 37
2
9 (L34-37)
8(L34-37)
≥ 6 hrs
≥ 6 hrs
≥ 6 hrs
1 (L1-4)
≥ 6 hrs
≥ 6 hrs
Principles of Chemistry
The course covers topics of General,
Inorganic and Organic Chemistry:
1. Stoichiometry and Reactions
2. Atomic Structure
3. Molecular Shape and Chemical Bonding
4. Main-Group Chemistry
5. Introductory Organic Chemistry
What is chemistry?
 the study of matter and energy and the interactions
between them.
 It tends to focus on the properties of substances and the
interactions between different types of matter,
particularly reactions that involve electrons.
 the study of substances and their
transformation
The building block of matter
Atom
Chemical Elements
Each elements is made of the same kind of atoms
Currently, there are about 118 elements discovered; some are
found in nature and some are man-made.
Elements carry the names and symbols.
Periodic Table
[Textbook p13-15]
Electronic configuration of atom
Chemistry is mostly the study of electron interactions between atoms and molecules.
Understanding the behavior of the electrons in an atom is an important part of
understanding chemical reactions.
The properties of an atom's electron configuration are described by four
quantum numbers: n, l, m, and s.
Orbitals that have the same principal quantum number, n, are part of the same
electron shell.
Orbitals that have the same n and l, they are in the same subshell.
Quantum numbers
Principal quantum number n. n is an integer (n = 1, 2, 3, 4,etc…), n defines
the size and the energy of the orbital (an electron shell).
Azimutal quantum number l, can be any number between 0 and (n-1). (l = 0, 1,
2, …,(n-1)), l defines the shape of the orbital (electron sub-shells).
Magnetic quantum number ml. can be any number between –l and +l. (m = -l,
-(l-1), …0, …, (l-1), l. ml defines the orientation of the orbital.
Spin quantum number ms can be + ½ or -½. ms describes the electron spin.
Electrons also have the further property of spin that can occur in two ways.
Notation: ms = +½ is noted ↑; ms = -½ is noted ↓.
The Building-Up Principle
THE PERIODICITY OF ATOMIC PROPERTIES
CHEMICAL BOND
Potential energy curves - Morse curves
When H – H distance = 74 pm,
Repulsion = Attraction
 strongest bond
 optimal overlap
 lowest energy
CHEMICAL BOND
Intramplecular
Intermolecular
The type of bond depends on the difference in electronegativity and
distribution of electron density
Bond type
Covalent
Ionic
Metallic
Types of atoms
involved
Mainly non-metals
Some non-metals
and some metals
Metals only
Nature of bonds
between atoms
Sharing of electrons
Transfer of
electrons
Delocalisation
of electrons
THEORIES OF CHEMICAL BONDING
Valence bond theory:
It explained the formation of covalent bonds between atoms, which is
supposed to be formed due to overlapping of atomic orbitals.
Molecular orbital theory:
The atomic orbitals of bonding atoms combine with each other by giving
rise to molecular orbitals. MO-LCAO
Molecular Shape
Valence Shell Electron Pair Repulsion Theory
VSEPR
A model in chemistry used to predict the shape of individual molecules based
upon the extent of electron-pair electrostatic repulsion. It is also named GillespieNyholm theory after its two main developers.
The geometry around an atom is described by the general formula: AXmEn ,
where X is a bonded atom, E is a lone pair and (m+n) is the number of objects
(sometimes called the steric number, SN) around the central atom A.
AX4 Tetrahedral
AX3E (Trigonal) Pyramidal
VSEPR Molecular Shapes
Summary of VSEPR Molecular Shapes
e-pairs
Notation
Name of VSEPR shape Examples
2
AX2
Linear
HgCl2 , ZnI2 , CS2 , CO2
3
AX3
Trigonal planar
BF3 , GaI3
AX2E
Non-linear (Bent)
SO2 , SnCl2
AX4
Tetrahedral
CCl4 , CH4 , BF4-
AX3E
(Trigonal) Pyramidal
NH3 , OH3-
AX2E2
Non-Linear (Bent)
H2O , SeCl2
AX5
Trigonal bipyramidal
PCl5 , PF5
AX4E
Distorted tetrahedral
(see-sawed)
TeCl4 , SF4
AX3E2
T-Shaped
ClF3 , BrF3
AX2E3
Linear
I3- , ICl2-
AX6
Octahedral
SF6 , PF6-
AX5E
Square Pyramidal
IF5 , BrF5
AX4E2
Square Planar
ICl4- , BrF4-
4
5
6
Stoichiometry
Law of Mass Conservation
The law of mass conservation implies that atoms can neither be
created nor destroyed during a chemical reaction, although they
may be rearranged, and/or their state of matter may change. The
direct implication of the law of mass conservation is that
chemical reaction equations must be balanced.
Types of Chemical reaction in Aqueous Solution
Precipitation/dissolution
Acid/base reactions (Brǿnsted-Lowry (B-L) )
Redox reactions
Oxidation-Reduction Reactions
Oxidation-Reduction Reactions in Aqueous Solutions
REDOX reactions can be balanced in one of two ways:
HCl + MnO2  Cl2 + MnCl2 + H2O
(1) The OXIDATION-STATE METHOD|| The oxidation number method.
(2) The HALF-EQUATION METHOD || The half reaction method. (ionelectron method)
MnO2 + 4 H+ +2 е-  Mn2+ + 2H2O
2 1
2 Cl- -2 е- Cl2
2 1
________________________________________
 equation
MnO2 + 4 H+ +2 Cl- +2 е-  Mn2+ + H2O+ Cl2 +2 е4 HCl + MnO2 = Cl2 + MnCl2 + 2 H2O
Chemistry of the Elements of the Main Group
Environmental Impact
of Main Group Compounds
ACID RAIN
OZONE DEPLETION
GREENHOUSE EFFECT
What is acid rain?
Acid rain typically has a pH from 4.0 to 5.4
What are the causes of acid rain?
SO2 , SO3, Nox
What are the effects of acid rain?
Damages buildings, statues
Corrodes marble and metals
Causes human respiratory
diseases
Increases the acidity of soil
Induces the release of aluminum
ions from soil particles
Acidifies lakes
What can we do to solve the problems brought by acid rain?
OZONE DEPLETION
Ozone layer in the stratosphere protects the Earth’s surface from UV light
Ozone depletion refers to a lowered concentration of ozone in the upper
atmosphere
“Holes” are formed  More UV radiation is reaching the Earth’s surface
What are the causes of ozone depletion?
Presence of chlorofluorocarbons (CFCs)
Presence of oxides of nitrogen
Presence of halogens
Presence of bromine
GREENHOUSE EFFECT
Greenhouse effect is an excess of heat created due to the high
concentrations of some gases
The 3 major greenhouse gases are:
water vapour (36 to 70%), carbon dioxide (9 to 26%), methane (4 to 9%).
Other contributors include nitrous oxide, ozone and CFCs.
Most of the incoming solar radiation is in the visible part of the spectrum
Most visible light passes through the atmosphere without being absorbed
The earth radiates heat back out towards space when warmed up
Much of the radiation does not escape into space
Most is trapped by certain gases in the atmosphere, carbon dioxide
and particular water vapour
What is global warming?
 Global warming refers to the gradual increase in the
average temperature in the atmosphere
Increase in concentration of greenhouse gases in the
atmosphere
The heat loss from the Earth to the Space is slowed down
An enhancement of the greenhouse effect leads to global
warming
Greenhouse gases include carbon dioxide,
chlorofluorocarbons, methane, nitrous oxides, ozone, water
vapour, etc
Thank you for attention!