Bonding Class #4 OB: become masterful with both the Double and the Triple Covalent Bonds, plus some...

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