BONDING REVIEW
Tuesday 10/13/15
Tuesday, October 13, 15
AGENDA
Topic 4 Bonding Review Questions
Tuesday, October 13, 15
TOMORROW
The lab is a mess... All counters and sinks must be
clean and empty!
You will also complete a check-in/out list to make
sure each item is in your drawer/cabinet.
Label outside of drawer with your name.
You and your partners will be responsible for this
drawer.
Tuesday, October 13, 15
THURSDAY
You will get a little more time to review your packet
of topic 4 practice questions (30 mins)
We will have the laptops and I will give you ample
time to work on your lab
Please go by what is in the email for this week’s
schedule not agenda, not the initial FB post from last
week (I decided to change it due to losing 25 minutes
Wednesday)
Tuesday, October 13, 15
LEWIS STRUCTURE
What is the correct Lewis structure for hypochlorous
acid, a compound containing chlorine, hydrogen and
oxygen?
A.
B.
C.
D.
Tuesday, October 13, 15
LEWIS STRUCTURE
What is the correct Lewis structure for hypochlorous
acid, a compound containing chlorine, hydrogen and
oxygen?
A.
B.
C.
D.
Tuesday, October 13, 15
BOND ANGLES
How do the bond angles in CH4, NH3 and H2O
compare?
A. CH4 = NH3 = H2O
B. CH4 < NH3 < H2O
C. NH3 < CH4 < H2O
D. H2O < NH3 < CH4
Tuesday, October 13, 15
BOND ANGLES
How do the bond angles in CH4, NH3 and H2O
compare?
A. CH4 = NH3 = H2O
B. CH4 < NH3 < H2O
C. NH3 < CH4 < H2O
D. H2O < NH3 < CH4
Tuesday, October 13, 15
BOND ANGLES
How do the bond angles in CH4, NH3 and H2O
compare?
Why is this the case??
A lone pair takes up more space (in VSEPR terms) than a bonded hydrogen. CH4 has only H
bonded to the central atom, NH3 has one pair of lone electrons, and H2O has two lone pairs
of electrons so the remaining hydrogens have to squeeze closer together.
Tuesday, October 13, 15
BOND STRENGTH
When C2H2, C2H4 and C2H6 are arranged in order of
increasing carbon-carbon bond strength (weakest bond
first), what is the correct order?
A. C2H2, C2H4, C2H6
B. C2H2, C2H6, C2H4
C. C2H6, C2H4, C2H2
D. C2H6, C2H2, C2H4
Tuesday, October 13, 15
BOND STRENGTH
When Ethene (C2H2), Etylene (C2H4) and C2H6 are
arranged in order of increasing carbon-carbon bond
strength (weakest bond first), what is the correct order?
A. C2H2, C2H4, C2H6
B. C2H2, C2H6, C2H4
C. C2H6, C2H4, C2H2
D. C2H6, C2H2, C2H4
Tuesday, October 13, 15
BOND STRENGTH
When Acetylene (C2H2), Ethylene (C2H4) and Ethane
(C2H6) are arranged in order of increasing carboncarbon bond strength (weakest bond first), what is the
correct order?
Why is this the case??
A single bond is called a sigma bond and it consists of the end-to-end overlap of hybrid
orbitals. Single bonds are the longest & weakest. A double bond is a sigma bond plus a pi
bond. A pi bond is the side-to-side overlap of unhybridized p-orbitals. A double bond
between the same two elements is shorter & stronger. A triple bond is a sigma bond plus
two pi bonds. A triple bond between the same two elements is shortest & strongest.
Tuesday, October 13, 15
PERIODIC TRENDS
Which combination of the characteristics of element X,
a metal, and element Y, a non metal, is most likely to
lead to ionic bonding?
Tuesday, October 13, 15
PERIODIC TRENDS
Which combination of the characteristics of element X,
a metal, and element Y, a non metal, is most likely to
lead to ionic bonding?
On right side of
periodic table
Tuesday, October 13, 15
On left side of
periodic table
PHYSICAL
CHARACTERISTICS
Explain why calcium has a higher melting point than
potassium and why sodium oxide has a higher
melting point than sulfur trioxide
Tuesday, October 13, 15
PHYSICAL
CHARACTERISTICS
Calcium has a 2+ charge (twice that of
potassium) and more delocalized
electrons in the s orbital than
compared to potassium - increasingly
more negative
Delocalization means the electron
doesn’t exist to a single atom - think of
it spread over the whole piece of metal.
Another way to conceptualize
delocalization is a “sea of electrons” ions surrounded by a sea of electrons.
Tuesday, October 13, 15
PHYSICAL
CHARACTERISTICS
Sodium oxide (Na2O) is a network solid with a number
of highly polar bonds which must be broken in order to
melt. It has an ionic bond with a stronger electrostatic
attraction between the Na+ ion and the O2- ion.
Sulfur trioxide (SO3) is a molecule and has weaker van
der Waals (dipole-dipole) attractions which are more
easily broken than ionic bonds. However, the S=O bonds
are stronger than the bonds within the Na2O molecules
but it is the intermolecular bonds that are broken in
order to make it melt, not the internal covalent bonds.
Tuesday, October 13, 15
LEWIS STRUCTURES
Ammonia, NH3, is a weak base. Draw the structure of
ammonia and state the shape of the molecule and its
bond angles.
The conjugate acid of ammonia is the the ammonium
ion, NH4+. Draw the Lewis Structure of the
ammonium ion and deduce its shape and bond
angles
Tuesday, October 13, 15
LEWIS STRUCTURES
Ammonia
Trigonal Pyramidal
Tuesday, October 13, 15
Ammonium ion
Tetrahedral
ISOTOPES
Define the term isotopes
A sample of silicon contains three isotopes:
Calculate the relative atomic mass using this data
Describe the structure & bonding of silicon dioxide
and carbon dioxide.
Tuesday, October 13, 15
RELATIVE ATOMIC MASS
CALCULATIONS
Ar = (massisotope 1)(abundanceisotope 1) + (massisotope 2)(abundanceisotope 2)
100
Tuesday, October 13, 15
STRUCTURE & BONDING
Describe the structure & bonding of silicon dioxide
and carbon dioxide.
SiO2 - single covalent bonds that form a network
solid arranged in tetrahedral geometries
CO2 - double covalent bond which is a simple
discrete molecule and does not form a network solid
Tuesday, October 13, 15