Bonding Class #4 OB: become masterful with both the Double and the Triple Covalent Bonds, plus some practice drawing structural diagrams for larger molecules

O 2 Oxygen How does it bond? (review) OO Each oxygen needs to gain 2 electrons to fill it’s valence orbital. Each oxygen must lend 2 electrons to the other.

O Will become… O Drawn structurally… this way: O=O Each 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) H 2 O 2 N 2 Cl 2 Br 2 I 2 F 2

Looking at the HONClBrIF twins, in order, let’s figure out the kinds of bonds that they all have… H 2 O 2 N 2 Cl 2 Br 2 I 2 F 2 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 We’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 Will shift → And structurally this will become: N Nitrogen shares 3 pairs of electrons, it makes a triple nonpolar covalent bond 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 C2H6C2H6 C2H4C2H4

Let’s draw electron dot diagrams and then STRUCTURAL diagrams for these compounds. DOTS Structural C2H6C2H6 C2H4C2H4 H―C―C―H H C H H H HH C C H C H H H

Let’s draw electron dot diagrams and then STRUCTURAL diagrams for these compounds. Name each bond type. DOTS Structural C2H2C2H2 C3H8C3H8

Let’s draw electron dot diagrams and then STRUCTURAL diagrams for these compounds. DOTS Structural C2H2C2H2 C3H8C3H8 C HH H―C C―H C C C H H HH H H H―C―C―C ― H H H H H-C bond is single polar covalent C-C bond is triple nonpolar covalent H-C bond is single polar covalent C-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 CO 2 AsCl 3

DOTS Structural CO 2 AsCl 3 O=C=O CO O Carbon dioxide is a STRAIGHT molecule Cl ―As―Cl Cl AsCl 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 C 3 H 8. Do the Structural Diagrams now. Name both kinds of bonds in this molecule

Propane formula is C 3 H 8. H―C―C―C―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 = 0.4 O Br O

Draw structural diagrams for carbon tetrachloride. Name the bonds between carbon and chlorine.

CCl 4 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 Cl Cl Cl―C―Cl Cl