1. BONDING, STRUCTURES & PROPERTIES PROPERTIES

2. After completing this topic you should be able to : BONDING, STRUCTURE & PROPERTIES PROPERTIES Carry out solubility tests to determine if ionic and covalent substances are soluble in water and other covalent solvents. Relate solubility of a substance to the bonding type in the solute and the solvent. Relate melting point and boiling point of a substance to the type of bonding in the substance. Relate the following properties: conduction of electricity solubilty in water and other solvents melting and boiling point to the type of bonding in a substance.

3. PROPERTIES Conduction of electricity is the only property that has been studied. SOLUBILITY, MELTING POINT and BOILING POINT are other properties which depend on the type of bonding in a substance. SOLUBILITY OF IONIC and COVALENT SUBSTANCES All metals are insoluble in water and other liquids. INVESTIGATION : SOLUBILITY of IONIC and COVALENT SUBSTANCES Test the solubility of some ionic and covalent substances in water and other solvents. CONCLUSION : What did you notice about the solubility of ionic substances in water and other liquids? What did you notice about the solubility of covalent substances in water and other liquids?

4. CONCLUSION Covalent substances are insoluble in water but are soluble in other covalent liquids (hexane and white spirit). Ionic substances are soluble in water but are insoluble in other covalent liquids (hexane and white spirit). Water, hexane and white spirit all have covalent bonding. Water is an unusual covalent liquid as it is a good solvent for ionic substances. Most covalent liquids are good solvents for covalent substances. Complete the SOLUBILITY OF IONIC AND COVALENT SUBSTANCES results table table on page 17 of the Bonding, Structure and Properties Notes.

5. MELTING AND BOILING POINTS The melting and boiling points of metallic, ionic and covalent substances can be obtained from the chemistry data booklet. INVESTIGATION : MELTING and BOILING POINTS Use the chemistry data booklet to find the melting and boiling points of the substances on the Melting / Boiling Point and Bonding Type table CONCLUSION : What did you notice about the size of the melting and boiling point and the type of bonding? Complete the MELTING AND BOILING POINTS table on page 18 of the Bonding, Structure and Properties Notes.

6. CONCLUSION Metals have high melting and boiling points and are solids at room temperature. Mercury is the only exception. Ionic substances have high melting and boiling points and are all solids at room temperature. Covalent substances have low melting and boiling points and can be solids, liquids or gases at room temperature. If a substance is a liquid or gas at room temperature, it will probably have covalent bonding. The noble gases and mercury are exceptions to this general statement.

7. BONDING AND PROPERTIES SUMMARY Type of Bonding Solubility in: Melting Point Boiling Point (s)(s)(s)(s) (l)(l)(l)(l) ( aq ) Conductivity c = conductor, i = insulator Water Other covalent liquids metallic ionic covalent c c c c Do not form solutions i i i i insoluble insoluble soluble insoluble insoluble soluble high high high high low low Complete the BONDING AND PROPERTIES table on page 19 of the Bonding, Structure and Properties Notes.