When the lesson is complete, students will be able to…..
Classify acids and bases according to their properties. => knowledge, comprehension, analysis, evaluation, inductive reasoning => 5e. Students know how to determine whether a solution is acidic, basic, or neutral.
Recognize acids as proton donors and bases as proton acceptors. => knowledge, comprehension, analysis, deductive reasoning => 5e. Students know how to determine whether a solution is acidic, basic, or neutral.
Interpret warning and safety labels on products containing acids and bases. => knowledge, comprehension, application, evaluation, critical thinking
Compare and contrast the strength of an acid or base with its concentration. => knowledge, comprehension, application, analysis, evaluation, inductive reasoning.
Describe the process of neutralization. => knowledge, comprehension, synthesis, deductive reasoning => 5a. Students know reactant atoms and molecules interact to form products with different chemical properties. 5c. Students know chemical reactions usually liberate heat or absorb heat. 5e. Students know how to determine whether a solution is acidic, basic, or neutral.
Explain how antacids work to reduce acidity. => knowledge, comprehension, application, synthesis, evaluation, deductive reasoning => 9a. Plan and conduct a scientific investigation to test a hypothesis.
Describe how indicators can be used to classify solutions as acidic or basic. => knowledge, comprehension, application, synthesis, evaluation, creative thinking
Compare and contrast normal rain and acid rain. => knowledge, comprehension, application, analysis, inductive reasoning
Compare the natural and industrial sources of acid rain. => knowledge, comprehension, application, analysis, synthesis, evaluation, inductive reasoning
List the effects of acid rain. => knowledge, application, evaluation
(C) Materials and Equipment
Activity 22.1 Properties of acids and bases in aqueous solution:
7 small test tubes, 2 corks to fit the test tubes, red and blue litmus paper, baking soda, magnesium turnings, vinegar, lemon juice, carbonated water, washing soda, soap solution, unknown solution (diluted ammonia water), 10mL graduated cylinder, safety goggles, lab apron
Demonstration 1: Disappearing ink available in many toyshops.
Demonstration 2: raw eggs of the same size, acetic acid solution, hydrochloric acid solution. Timer.
Demonstration 3: a head of red cabbage, heating mantle, vinegar, baking soda, ammonia water, 0.1 M HCl solution
(E) Lesson activity Warm-up/Dispatch Activity
Section 22.1: Vocabulary – find the meaning of the vocabulary listed in the board with your textbook glossary. (5 min.)
Taste of Foods: write down the names of foods you ate this morning and their tastes.
Section 22.2: Vocabulary – find the meaning of the vocabulary listed in the board with your textbook glossary. (5 min.)
Introduction. How does today's lesson relate to past lessons?
Introduction of Chapter 22. and Section 22.1.1 (10 min.)
Read and answer the question: Why do some hydrangeas have pink flowers, while others have blue flowers? (Text book pp.540~541)
This chapter is a part of Unit 7 ‘chemical system’ which consists of chapter 21. Chemical reactions, chapter 22. Acids, bases and salts, and chapter 23. The environmental and chemical technology. In this unit, students learn about what happens and how it affects our life when chemical reactions take place. Especially, Chapter 22. Acids, Bases and Salts is introduced as a representative chemical reaction which is closely related to our life. From this chapter, students will learn how to classify substances based on their properties and what indicates a chemical reaction (neutralization) occurring. These are review of former Unit. 5 Matter and former Chapter. 21.
Look at the concept map of the chapter.
Introducing Learning objectives
Section 22.1.2: Demonstration –Disappearing ink
Disappearing ink contains the indicator thymolphthalein. When squirted onto a cloth, the blue color is visible. This will dissipate as the CO2 gas from the atmosphere dissolves into the solution and neutralize the slightly basic solution. I will challenge students to explain this phenomenon. This demonstration shows that CO2 gas is an acid anhydride of carbonic acid.
Section 22.2: Neutralization and pH
Acids and bases are substances. And substances undergo chemical reactions. When an acid reacts with a base, both of them lose their properties and become new substances. How do we know a chemical reaction take place, especially neutralization reaction?
Watch a demonstration with red cabbage juice and answer the question: What causes the color change of red cabbage juice?
Section 22.3: Acid Rain
The concept of acid rain is related to the concept of pH and acid anhydride. Most pollutants of acid rain are nonmetallic oxides, which are acid anhydride.
Lecture/discussion (Lecture notes)
Section 22.1 Recognizing Acids and Bases Common properties of acids and bases dissolved in water(Textbook p.542~544)
Classify acids and bases according to their properties.
Emphasize that as elements are grouped in the periodic table in terms of their atomic structures and properties, chemical compounds can be grouped according to their properties.
During the lab activity, students will fill out handout 1.
After lab activity 22.1(it takes 30 min.), discuss the general properties of acids and bases as an activity of drawing conclusions.
During the activity, the hydrogen gas will be identified by combustion as a teacher demonstration. This confirms that every acid has hydrogen atom in its molecule. I will use this fact when the definition of acids is taught.
During this activity, students will develop inductive reasoning skills finding common properties of acids and bases.
The properties will be summarized a table as a graphic organizer with two columns (diagram 1) to make it easy to compare and contrast the properties of acids and bases.
I will challenge students to compare the results of their knowns and the unknown I provide. I use diluted ammonia solution as an unknown solution. This fact will be used when I teach the definition of bases.
I give them a chemical equation that explains the reaction of acids with carbonates and metals.