Upload
peter-stephens
View
215
Download
1
Embed Size (px)
Citation preview
Principles of Chemistry
Introduction to the Principles of Chemistry
Rena AbbasovaBaku Higher Oil School, September 2013
Text book:Chemistry, 2nd Editionby Blackman, Bottle, Schmid, Mocerino and Wille
Reference to book pages on notes e.g. [T p15-20]
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 ≥ 6 hrs
2 4-6 2 1 (L1-4) ≥ 6 hrs
3 7-10 2 ≥ 6 hrs
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 ≥ 6 hrs
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
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
Chemical ElementsEach 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.
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.
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 ↓.
Quantum numbers
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
CHEMICAL BOND
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 TheoryVSEPR
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 Gillespie-Nyholm 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
e-pairs Notation Name of VSEPR shape Examples2 AX2 Linear HgCl2 , ZnI2 , CS2 , CO2
3 AX3 Trigonal planar BF3 , GaI3
AX2E Non-linear (Bent) SO2 , SnCl2
4 AX4 Tetrahedral CCl4 , CH4 , BF4-
AX3E (Trigonal) Pyramidal NH3 , OH3-
AX2E2 Non-Linear (Bent) H2O , SeCl2
5 AX5 Trigonal bipyramidal PCl5 , PF5
AX4E Distorted tetrahedral (see-sawed)
TeCl4 , SF4
AX3E2 T-Shaped ClF3 , BrF3
AX2E3 Linear I3- , ICl2
-
6 AX6 Octahedral SF6 , PF6-
AX5E Square Pyramidal IF5 , BrF5
AX4E2 Square Planar ICl4- , BrF4
-
Summary of VSEPR Molecular Shapes
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
Stoichiometry
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. (ion-electron method)
MnO2 + 4 H+ +2 е- Mn2+ + 2H2O 2 12 Cl- -2 е- Cl2 2 1________________________________________ equationMnO2 + 4 H+ +2 Cl- +2 е- Mn2+ + H2O+ Cl2 +2 е-
4 HCl + MnO2 = Cl2 + MnCl2 + 2 H2O
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, statuesCorrodes marble and metalsCauses human respiratory diseasesIncreases the acidity of soilInduces the release of aluminum ions from soil particlesAcidifies 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 nitrogenPresence of halogens Presence of bromine
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 spectrumMost visible light passes through the atmosphere without being absorbedThe earth radiates heat back out towards space when warmed upMuch of the radiation does not escape into spaceMost is trapped by certain gases in the atmosphere, carbon dioxide and particular water vapour
GREENHOUSE EFFECTGreenhouse effect is an excess of heat created due to the high concentrations of some gases
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