Flipped - Chemical Bonding

Chemical Bonding - Flipped Learning

Skating on water

Surface Tension exists in water because water molecules stick each other. Water has high surface tension, which means the molecules are strongly pulling each other together on the surface. Even though the paperclip has higher density than the water, the strong attraction between the water molecules on the surface forms a type of “skin” that supports the paperclip. When you put a drop of dish soap in the water, it binds with the water molecules, interfering with the surface tension, and allowing the higher density paperclip to sink.

The electrostatic attraction between positive ions (cations) and negative ions (anions) in an ionic crystal lattice. Sometimes called an electrovalent bond.

Ionic bonding

When two non-metal atoms combine, they share one or more pairs of electrons

Covalent bonding

This kind of bond form when one atom provides both the electrons needed for a covalent bond

Co-ordinate bonding

Overview

• The ionic or covalent bonds formed are usually very strong; means it takes a lot of energy to break them

• As within the molecules are held by strong covalent bonds, there are forces that holds in between the molecules, which is weak.

• This weak forces are called van der Waal's forces

• The term van der Waal's forces is a general term to describe all intermolecular forces

Types of van der Waal's forces

1. Dipole (instantaneous dipole-induced dipole (id-id) forces, also called London dispersion forces.)

2. Permanent dipole-permanent dipole (pd-pd) forces

3. Hydrogen bonding, stronger than pd-pd forces

Van der Waals Forces: Meaning & importance | StudySmarter

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Reorder

Arrange the strength of the force

• Electrostatic force (Ionic bond)

• Covalent bonding

• van der Waal's force

1

2

3

• 1
• 2
• 3

Multiple Choice

What is the other name of ionic bond?

• electrostatic bond

• valent bond

• electrovalent bond

• static bond

• outer electron only

• the charge of the ions, using square bracket

• charge of each ion is written on top right-hand corner

A dot-and-cross diagram shows:

• The dot-and-cross diagram shows the electronic configuration of the magnesium and oxygen ions.

• This helps us to keep track of where the electrons have come from.

• By losing 2 electrons, the magnesium atom achieves the stable electronic configuration [2,8]

• By gaining 2 electrons on the other hand, oxygen also achieve the stable octet electron configuration [2,8]

Draw

Draw dot-and-cross diagrams for the ions of sodium oxide, Na2O.

Covalent bonding

• When two non-metal atoms combine, they share one or more pairs of electron

• One shared pair of electrons is called a single covalent bond or a bond pair

• any pairs of electron in the outer shell of an atom that are not involved in bonding is called lone pairs of electron

• the sign is indicated by sign '-'

• e.g Cl-Cl, H-H, Br-Br

The lone pairs of electron is the unbonded electrons

Lone pair of electron

Draw

Draw a dot-and-cross diagram of phosphorus(III) chloride

Double covalent bond

• A double covalent bond takes place when some atoms share two pairs of electrons

• The double bond is indicated by the sign '='

• e.g. O=O, O=C=O

Draw

Draw dot-and-cross diagrams for carbonyl chloride, O=CCl2

Co-ordinate bonding

• A co-ordinate bonding (or dative covalent bond) is formed when one atom provides both the electrons needed

• For this bonding to take place:

  • one atom having a lone pair of electron

  • the second atom have an unfilled orbital to accept the lone pair (electron-deficient compound)

Co-ordinate bonding

• A co-ordinate bond is represented by an arrow.

• The head of the arrow points away from the lone pair to the atoms with the empty orbital

1. Hydrogen has an empty 1s orbital (making it to form H+ ion)

2. Lone pair from the ammonia molecule will provide its lone pair electron to fill the 1s orbital and form a co-ordinate bond with the H+ ion

3. The arrow indicate the lone pair is shared by the ammonia towards the Hydrogen ion

The net charge for ammonium is +1 is due to the number of proton in the ammonium compound is more than the total number of electrons.
5 protons from nitrogen and 4 protons from hydrogen = 9 proton (9+)
5 electrons from nitrogen and only 3 electron from hydrogen = 8 electron (8-)

Total net charge = 9+ + (8-) = +1

Draw

Draw a dot-and-cross diagrams to show the formation of a co-ordinate bond.

boron trifluoride, BF3 and ammonia, NH3, to form F3BNH3. **Show the co-ordinate bond by an arrow.

Draw

Draw a dot-and-cross diagrams to show the formation of a co-ordinate bond.

phosphine, PH3, and a hydrogen ion, H+ to form the ion PH4+. **

Show the co-ordinate bond by an arrow.