The Chinese University of Hong Kong PGDE The Chinese University of Hong Kong PGDE Presentation Package for a Chemistry Lesson ACIDS

Author List Group 4 Name Duty Chan Pui Sze Photo Scanning & information Collection Lee Suk Ching Sound Effect & Information Collection Sin Wai Ling Graphics & information Collection Yick Ho Kuen Slide Design & Information Collection

Part 1Introduction Part 2What are the properties of acids? What precautions we have to take in diluting acid? Part 3Daily examples of acids Part 4Follow-up questions

F.4 chemistry students with average ability at the average age of 15 come across daily products containing acid most are active

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

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

What acidic substance can we find in daily life?

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

Acids show a pH test colour of orange or red.

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

All dilute acids can conduct electricity.

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

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

Dehydration of sugar sugar + acid  carbon + 

Volatile

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

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

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

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

Our stomach secretes hydrochloric acid to help us digest food.

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

water Adding concentrated acid

Wearing goggle Wearing gloves

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

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