1. Acid and Bases -Types of Oxides- Many acids and alkali are formed by dissolving oxides in water

2. At the end of this e-learning, you should able to: Classify oxides as acidic, basic, amphoteric or neutral based on metallic/non-metallic character

3. What is an oxide? An oxide is a compound of oxygen and another element. Most oxides can be grouped into four types: acidic oxides basic oxides amphoteric oxides neutral oxides

4. Acidic oxides Oxides of non-metal Acidic oxides are often gases at room temperature.

5. Acidic oxides React with water to produce acids. Example: sulphur trioxide + water sulphuric acid SO 3 + H 2 O H 2 SO 4

6. Acidic oxides React with bases and alkalis to produce salts Example: carbon dioxide + sodium hydroxide sodium carbonate + water CO 2 + 2NaOH Na 2 CO 3 + H 2 O

7. Examples of acidic oxides Acidic Oxide Formula Acid Produced with Water sulphur trioxideSO 3 sulphuric acid, H 2 SO 4 sulphur dioxideSO 2 sulphurous acid, H 2 SO 3 carbon dioxideCO 2 carbonic acid, H 2 CO 3 phosphorous(V) oxide P 4 O 10 phosphoric acid, H 3 PO 4

8. Basic oxides Oxides of metal Basic oxides are often solids at room temperature. Most basic oxides are insoluble in water. Calcium oxide (quicklime)

9. Basic oxides React with acids to produce salts and water only. Example: Magnesium oxide + hydrochloric acid magnesium chloride + water MgO + 2HC l MgC l 2 + H 2 O This is a neutralisation reaction

10. Examples of basic oxides Basic Oxide Formula magnesium oxideMgO sodium oxideNa 2 O calcium oxideCaO copper(II) oxideCuO

11. Amphoteric oxides Oxides of metal Can behave as acidic oxides or as basic oxides Zinc oxide

12. Amphoteric oxides React with acids and alkalis to produce salts Example: aluminium oxide (Al2O3) aluminium oxide as a base aluminium oxide as an acid hydrochloric acid aluminium chloride water aluminium oxide ++ sodium hydroxide sodium aluminate water + +

13. Neutral oxides Non-metals that form oxides that show neither basic nor acidic properties. Insoluble in water.

14. Examples of neutral oxides Neutral Oxide Formula waterH2OH2O carbon monoxideCO nitric oxideNO

15. How can we classify an unknown oxide? First question: Does the oxide dissolve in acid? YESNO

16. It is either a basic or amphoteric oxide. Next question: Is the oxide soluble in alkali? SolubleInsoluble

17. It is either an acidic or neutral oxide. Next question: Is the oxide soluble in alkali? SolubleInsoluble

18. Amphoteric oxide What is an amphoteric oxide? Back to first question

19. Basic oxide What is a basic oxide? Cook an egg with calcium oxide Back to first question

20. Acidic oxide What is an acidic oxide? How does acidic oxide affects the atmosphere? Back to first question

21. Neutral oxide What is an neutral oxide? Back to first question Back to the first slide