| Subject
Area |
Introduction to the properties of acids and bases. |
| Age
or Grade |
11th or 12th grade students |
| Estimated
Length |
Two class periods |
| Prerequisite
knowledge/skills |
Basic understanding of chemistry. Better for students later in the school year. |
| Description
of New Content |
Chemical properties that define an acid, base and neutral compounds. Introduction of pH scale. |
| Goals |
Using everyday household products, introduce students to the ideas behind acids and bases and what makes them so different from one another. Also, introduces the students to the pH scale and its properties. |
| Materials
Needed |
Red Cabbage, selection of 7-9 household products that are either acid, or base. (lemon juice, ammonia, vinegar, alcohol, orange juice, milk of magnesia, baking soda etc...), several beakers and test tubes. |
|
Procedure
|
Opener - Introduce the red cabbage, and how its pigment works as an indicator. Have the students define indicator, acid, base, neutral, pH. Development - Once the students have a basic understanding, have them add a small amount of red cabbage indicator to each household sample and monitor the color change. Once this is complete, have the students group the items together based on color and discuss eah compounds properties. Closure - Make the conclusion that substances that react similarly with the red cabbage indicator have similar structural characteristics. Show the students where on a pH scale each compound would be found with the corresponding colors. |
| Evaluation |
Follow up quiz on pH and acids and bases. |
| Extensions |
This lesson could go on for an extra amount of time depending on how in depth you wanted to take the ideas behind acids and bases, and the chemical differences that exist. |