2. Part 1Introduction Part 2What are the properties of acids? What precautions we have to take in diluting acid? Part 3Daily examples of acids Part 4Questions

3. In this lesson, we use pictures to recall students’ memory photos and graphics to show the properties of acid sound effect in the quiz

4. Introduction of acids in daily life Properties of acids Common use of acids Danger of acids A small quiz

5. What acidic substance can we find in daily life?

6. Most acids have a sour taste. The word “acid” means “sour”.

7. Acids show a pH test colour of orange or red.

8. Acidity can be measured by pH meter. Acids show the pH in the range from 1 to 6.

9. All dilute acids can conduct electricity.

10. Concentrated acids are very corrosive and represented by a symbol as :

11. Corrosive properties of acids On metal On cloth/paper Acid rain on marble Metal terminal of battery

12. Dehydration of sugar sugar + acid  carbon + 

13. Volatile

14. Fruits (e.g. oranges, lemons and pineapples) contain citric acid Common Household Acids

16. Soft drinks contain carbonic acid. Vinegar and tomato sauce contain ethanoic acid.

17. Yoghurt and sour milk contain lactic acid. Tea contains tannic acid.

18. Domestic cleaners contain methanoic acid. Car battery contains sulphuric acid.

19. Our stomach secretes hydrochloric acid to help us digest food.

20. Concentrated acid Adding water A lot of heat is given out and cause acid to jump out.

21. water Adding concentrated acid

22. Wearing goggle Wearing gloves

23. Click T or F for the correct answer. For correct answer For incorrect answer 1. Vinegar is a dilution solution of ethanoic acid. T/F 2. Most acids have a bitter taste. T/F 3. Acids can turn litmus paper from red to blue. T/F 4. Acid-alkali neutralizations produce salts. T/F 5. When you dilute a concentrated acid, always add the acid slowly to a large amount of water.T/F