Search for notes by fellow students, in your own course and all over the country.
Browse our notes for titles which look like what you need, you can preview any of the notes via a sample of the contents. After you're happy these are the notes you're after simply pop them into your shopping cart.
Document Preview
Extracts from the notes are below, to see the PDF you'll receive please use the links above
Introduction to
Foundation of Chemistry
I
Jully Tan
School of Engineering
1
Learning Outcome
This lecturer is intended to re-flash the students of the basic of chemistry
...
Understand the structure & bonding (Lewis Structure) in organic chemistry
...
School of Engineering
EP101 / EG101
2
1
Revision : Electron Configuration
To getting start of the class…
...
and answer the below:
What is the different between atomic number and mass number?
What is isotopes?
How many electrons, protons and neutrons do each of the following atom have?
(a) carbon: mass number = 12 and mass number =13
(b) chlorine: mass number=35 and mass number =37
School of Engineering
EP101 / EG101
3
Atomic Structure
•1 shell consists of :
•1s subshell holding the max of 2 electrons
•2 shell consists of:
•2s subshell holding the max of 2 electrons
•2p subshell holding the max of 6 electrons
•2px, -max of 2 electron
•2py, -max of 2 electron
•2pz -max of 2 electron
•3 shell consists of:
•3s subshell holding the max of 2 electrons
•3p subshell holding the max of 6 electrons
•3d subshell holding the max of 10 electrons
School of Engineering
EP101 / EG101
4
2
Atomic Structure
Electrons occupy orbitals which are grouped into subshells and
then shells
...
Rule 1- Pauli’s Exclusion Principle: In any 1 atom, no 2 electrons may have all 4 quantum
number
...
Rule 2-Aufbau (“Build-Up”) Principle: Orbitals fill in order of increasing energy
from lowest energy to highest energy
...
4p
3d
4s
energy
3p
3s
2p
2s
1s
School of Engineering
EP101 / EG101
6
3
Electronic Configuration of Atoms
School of Engineering
EP101 / EG101
7
Hybridization & Molecular Shape
Reaction of compounds results in hybridization to form different molecular shapes
by the inter-reaction of simple s and p orbital of different atom
...
- a hybrid of 1 s and 3 p orbital
...
5º
...
- A hybrid of 1s & 2p orbitals
...
- Since only 3 bonded atoms are needed to arranged in space, the s & 2p
orbitals are combined to form new orbital sp2
...
- A hybrid of 1s & 1p orbitals
...
- The triple bond is composed of a σbond and 2π bonds
...
geometry
sp
VSEPR
groups
linear
Orbitals
2
Where
found
#
Pi bonds
2
C
C
sp2
trigonal planar
3
1
C
sp3
tetrahedral
4
0
C
EP101 / EG101
School of Engineering
11
Bonding strength
>
>
Bonding length
<
<
Bonding energy
>
School of Engineering
>
EP101 / EG101
12
6
Draw the hybridization structure diagram of
CH3CHCHCCH
School of Engineering
EP101 / EG101
13
Type of bonding
To be fulfill the octet rule: when atoms form ions or combine in compounds
they obtain electron configurations of 8 outer electrons
...
Ionic bonding: between metal and non-metal
...
Ionic Bonding: Electrons can be transferred to an atom to produce an anion and
“complete the octet”
...
The shared electrons typically “complete the octet” for each atom
...
School of Engineering
EP101 / EG101
14
7
Ionic Bonding
Ionic bonding:
i
...
Charged particles or ions
iii
...
Atoms in Group 1A, 2A & 7A
...
An example is methane: A neutral carbon atom with 4 electrons in its outer valence
shell can share electrons with 4 neutral hydrogen atoms with one electron each in
their outer valence shells
...
One electron
from carbon is shared with each hydrogen atom and fills the hydrogen atom’s
valence shell to the preferred 2 electrons
...
More than any other element, carbon tends to share electrons with atoms of its own
kinds
...
Rules
i
...
Each C atoms assumed to be present when 2 lines meet or line begins/ends
...
Each C atom is assumed to have enough H atoms (which each C has total of 4
bonds)
iv
...
v
...
C3H8
CH3CH2CH3
skeletal
H3C CH2 CH3
Condensed structure
School of Engineering
EP101 / EG101
18
9
Electronegativity
It define as the tendency for an atom to attract a pair of electrons that it
shares with another atom
...
Electronegativity increase across the Periodic Table and decrease down a
group
...
of charges on nucleus increase, bonding electrons are attracted
more strongly
...
That means that the B end of the bond has more than its fair share of electron density and so
becomes slightly negative
...
In the diagram, "" (read as "delta") means "slightly" - so + means "slightly
positive"
...
Inductive effects
An atom like fluorine which can pull the bonding pair away from the atom it is attached to is
said to have a negative inductive effect
...
You will come across some groups of atoms which have a slight positive inductive effect - they
"push" electrons towards the carbon they are attached to, making it slightly negative
...
Identify each compound as ionic or covalent:
- MgO
- CaCl2
- SO2
- CCl4
2
...
Draw lewis structure and lewis dot diagrams to represent the following compounds:
- SO2
- CCl4
- PCl3
School of Engineering
EP101 / EG101
23
4