bonding class #4 ob: become masterful with both the double and the triple covalent bonds, plus some...
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Bonding Class #4
OB: become masterful with both the Double and the Triple Covalent Bonds, plus some practice drawing structural diagrams for larger molecules
O2 Oxygen How does it bond? (review)
O OEach oxygen needs to gain 2 electrons to fill it’s valence
orbital. Each oxygen must lend 2 electrons to the other.
O OWill become…
O O Drawn structurally… this way: O=OEach O has a 3.4 electronegativity value, so this is a
Double Non-Polar Covalent Bond
Looking at the HONClBrIF twins, in order, let’s figure out the kinds of bonds that they all have… (draw dots or structural's to think)
H2
O2
N2
Cl2
Br2
I2
F2
Looking at the HONClBrIF twins, in order, let’s figure out the kinds of bonds that they all have… H2
O2
N2
Cl2
Br2
I2
F2
Single non-polar covalent H―H
Double non-polar covalent O=O
???
Single non-polar covalent Cl―Cl
Single non-polar covalent Br―Br
Single non-polar covalent I―I
Single non-polar covalent F―F
Time for some
Thinking!
N NWe’ll need two nitrogen atoms, which both need to follow the octet rule. How many electrons do they need to borrow from each other? To do that, we’ll
have to rearrange the electrons so that they can share them with each other.
N N Will shift →
And structurally this will become:
N NNitrogen shares 3 pairs of electrons, it makes a
triple nonpolar covalent bond
N N
Covalent bonds are between 2 or more nonmetals, and usually follow the octet rule.
Covalent bonds can be:
SINGLE, DOUBLE, or TRIPLE
They can also be:
POLAR or NON-POLAR
Let’s draw electron dot diagrams and then STRUCTURAL diagrams for these compounds.
DOTS Structural
C2H6
C2H4
Let’s draw electron dot diagrams and then STRUCTURAL diagrams for these compounds.
DOTS Structural
C2H6
C2H4
H―C―C―H
H H
H H
C C H H
H H
H H
C C
H H
H H
C C H H
H H
Let’s draw electron dot diagrams and then STRUCTURAL diagrams for these compounds. Name each bond type.
DOTS StructuralC2H2
C3H8
Let’s draw electron dot diagrams and then STRUCTURAL diagrams for these compounds.
DOTS Structural
C2H2
C3H8
C CH H H―C C―H
C C C H H
H H
H HH
H
H―C―C―C―H
H H H
H H H
H-C bond is single polar covalentC-C bond is triple nonpolar covalent
H-C bond is single polar covalentC-C bond is single nonpolar covalent
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Let’s draw electron dot diagrams and then STRUCTURAL diagrams for these compounds. Name each bond type.
DOTS Structural
CO2
AsCl3
DOTS Structural
CO2
AsCl3
O=C=OC O OCarbon dioxide is a STRAIGHT molecule
Cl―As―Cl
Cl
As ClCl
Cl
O = C bond is a double polar covalent bond
As – Cl bond is a single polar covalent bond
Propane goes camping with some people in blue tanks, to run the stoves. It’s a repeating type molecule, a little chain really. The formula is C3H8. Do the Structural Diagrams now. Name both kinds of bonds in this molecule
Propane formula is C3H8.
H―C―C―C―H
H H H
H H H
The C―C bond is single nonpolar covalent
and the C―H bond is single polar covalent
Draw Dot diagrams and structural diagrams for oxygen dibromide. Name the bonds between bromine + oxygen.
Structurally, this becomes…
These bonds are SINGLE POLAR COVALENT bonds.
EN diff of 3.4 - 3.0 = 0.4
O Br
Br OBr
Br
Draw structural diagrams for carbon tetrachloride.
Name the bonds between carbon and chlorine.
CCl4 The Electronegativity difference between Cl - C is 3.2 – 2.6 = of C is 0.6, These are all
single polar covalent bonds.
Cl C ClCl
ClCl―C―Cl
Cl
Cl