Lesson 2

OBJECTIVES

You have completed this lesson when you can:

1. Distinguish between observation and inference.

2. Use observations to distinguish between chemical and physical changes. Recognize chemical reactions by observation or description of the observable changes that take place.

3. Handle chemicals properly--safely and without contamination.

4. Write clear, concise descriptions of chemical reactions. (Note that explanations of chemical reactions will come later.)

5. State or recognize statements of the Law of Conservation of Mass and apply the law where appropriate.

6. Given the weight relationships in a chemical reaction, calculate the amount of a chemical that will react with (or produce or be produced by) a specified amount of another chemical.

7. Identify the limiting reagent (and the excess reagent) in a chemical reaction given specified amounts of two reactants.

8. Calculate the amount of a chemical that will react with (or be produced by) a limiting reagent given the necessary information about the weight relationships.

9. Calculate the composition (in weight percent) of a compound or solution given the weights of the components.

10. Explain what is meant by the Law of Constant Composition, as well as stating it or recognizing it or identifying examples of it. Use it to distinguish between compounds and other classes of materials.