chemical bonds- properties of ionic and covalent compounds

CHEMICAL BONDSPROPERTIES OF IONIC & COVALENT COMPOUNDS

LEARNING OUTCOME

At the end of this lesson, you should be able to:• List the properties of Ionic compounds• List the properties of Covalent compounds.• Explain the differences in electrical conductivity of ionic and

covalent compounds.• Describe the differences in melting and boiling points of ionic and

covalent compounds.• Compare & contrast the solubility of ionic and covalent

compounds.• State the uses of covalent compounds as solvent

IONIC VS COVALENT

ACTIVITY

1. Discuss in your group regarding:- Properties of ionic and covalent compounds- Use of covalent compounds in daily life

2. Write down your discussion on the manila card given.

3. Present it in the front of the class.

IONIC COMPOUNDS

• Polarity: The ionic bonds are polar in nature as there are positive and negative ions due to electronegativity difference.

• Solubility: Because of polarity they are soluble in polar solvents.

• Strength: The strength of ionic bond is high due to strong coulomb’s forces.

COVALENT COMPOUNDS

• Polarity: The covalent compounds are non-polar in nature as there are no positive and negative ions.

• Solubility: not soluble in polar solvent because it is a non-polar.

• Strength: The strength of covalent bond is weaker due to lack of coulomb’s forces.

COLOUMB FORCE

• The Coulomb force between two or more charged bodies is the force between them due to Coulomb's law. If the particles are both positively or negatively charged, the force is repulsive; if they are of opposite charge, it is attractive.

PROPERTIES OF IONIC & COVALENT COMPOUNDS

PROPERTIES IONIC COMPOUNDS COVALENT COMPOUNDS

Shape exist as solid in room temperature

may exist as solids, liquid or gases

Melting & Boiling points High Low

Electricity Conductivity Conduct electricity in aqueous solution or molten state

Do not conduct electricty

Solubility in Water Soluble Insoluble

Solubility in Organic Solvent Insoluble Soluble

ELECTRICAL CONDUCTIVITY

• In solid ionic compounds, ions are fixed in positions in the crystal lattice structure and do not move freely. Hence, an ionic compound does not cond~ct electricity in the solid state. However, in aqueous solution or molten state, ions are free to move. Therefore, the comppund can conduct electricity

• Covalent compound consists of neutral molecules. Hence, covalent compounds do not conduct electricity in all states.

ELECTRICAL CONDUCTIVITY

MELTING & BOILING POINTS

• The ions in ionic compounds are held together by strong ionic bonds. It would take a lot of energy to overcome the strong electrostatic forces that are holding the ions together. This explains why ionic compounds have high melting and boiling points.

• Molecules in covalent compounds are held together by weak intermolecular forces. Thus, less heat energy is required to overcome these forces. This explains why covalent compounds have low melting and boiling points.

SOLUBILITY

• Most ionic compounds are found to be soluble in water but are insoluble in organic solvents.

• On the other hand, most covalent compounds are insoluble in water but can dissolve in organic solvents.

SOLUBILITY

USE OF COVALENT COMPOUNDS AS SOLVENT

• Alcohol, ether and acetone are use as a solvents

• Widely use in various fields in our daily life.

HOMEWORK

• State threedifferences in properties between ionic and covalent compounds.

• Explain why ionic compounds have higher melting points than covalent compounds.

• What are the properties of ethanol that make it suitable to be used as a solvent?

CONCLUSION

PROPERTIES IONIC COMPOUNDS COVALENT COMPOUNDS

Shape exist as solid in room temperature

may exist as solids, liquid or gases

Melting & Boiling points High Low

Electricity Conductivity Conduct electricity in aqueous solution or molten state

Do not conduct electricty

Solubility in Water Soluble Insoluble

Solubility in Organic Solvent Insoluble Soluble