The Expanding Universe
Chemical Reactions Continued
Author Name: Chris Curran
Subject: Middle School Science
Period: 1st (100 minute block)
Date: 7/8/09
Objectives:
1. TSW recognize the parts of a chemical equation, namely coefficients, products, reactants, etc. (DOK1, 8Sci-2a)
2. TSW recognize the chemical equations for chemical respiration and photosynthesis. (DOK1, 8Sci-2a)
Materials:
Teacher:
Overhead projector, overhead pens, transparency
Art supplies
Alka-Seltzer
Water
Beaker
Do Now: (4 min)
1. Give an example of a chemical change/reaction.
2. Give an example of a physical change.
3. What makes a physical change different from a chemical reaction?
Set: (5 min)
1. TTW have the students provide answers to the Do Now questions.
2. TTW begin to become concerned about the students. TTW ask the students if they realize that breathing ‘that’ in will make dihydrogen monoxide in their bodies. TTW continue to get the student alarmed, asking why they don’t see what is going on right in front of their face.
3. TTW eventually concede that he is merely talking about the chemical reaction happening when the students breathe. TTW explain that today the class will be continuing the discussion of chemical equations and in part looking at the chemical reaction/equation of respiration and photosynthesis. TTW go over the days objectives.
4. TTW tell the students that chemical reactions/equations are relevant to their everyday life because they show up in things as important as breathing.
Procedure: (91 min)
1. TTW have students work through the parts of a chemical equation. TSW call out terms such as “reactant” and “product”. TTW label the parts of a chemical equation on the white board. TTW then right the definition of the part called out. TSW take notes on the definitions.
2. TTW go over synthesis and decomposition reactions. TTW review the terms “reactant” and “product” while going over these reactions.
3. TTW hand out the chemical equations worksheet. TSW label reactants and products. TSW also label reactions as synthesis, decomposition, or other as appropriate.
4. TCW go over the answers to the chemical equations worksheet.
5. TTW tell the class that they are now going to put their knowledge of chemical reactions to the test by applying the terms they learned to a real chemical reaction.
6. TTW perform a demonstration in which a sodium bicarbonate tablet (Alka-Seltzer equivalent) is placed in water resulting in the production of a gas.
7. TCW create a chemical equation for the reaction performed in the demonstration. An example of a suitable equation might be something like H2O + Alka-Seltzer = Gas The details of the reaction are not important at this point.
8. TSW label the parts of the reaction using terms such as “reactant”, “product”, “coefficient”, etc. TSW classify the reaction as a decomposition, synthesis, or other reaction.
9. If time permits, TCW go over the worksheet assigned as homework in the previous lesson. Reviewing the answers to this homework will serve as a review for chemical equations.
10. TCW take a 3 minute break.
11. TTW have the student call upon previous knowledge of photosynthesis and respiration to construct a rough equation representing photosynthesis and respiration. Such an equation might look something like the following: Respiration: oxygen = carbon dioxide. Photosynthesis: carbon dioxide = oxygen + food
12. TTW work with the rough chemical equations by replacing words such as “food” with glucose and its corresponding chemical formula. TTW lead the students to see that they already knew the basics of the equation and are just filling in the little details of the chemical equations.
13. TTW assign an art project in which the student is to draw pictures representing photosynthesis and respiration. TSW include the role of humans, plants, etc. TSW draw the chemical formulas on the picture.
14. TTW administer a short quiz.
Closure: (5 min)
1. TTW remind the student of the objectives. The teacher may ask the student to recall the objectives.
2. TTW ask questions of the students regarding the material covered in the lesson. TSW provide answers.
3. TTW tell the students that tomorrow’s lesson will be a break from chemistry but that on Friday the class will be continuing the work with chemical formulas by looking at the balancing of chemical equations.
Assessment/Evaluation:
Objective:
TSW recognize the parts of a chemical equation, namely coefficients, products, reactants, etc. (DOK1, 8Sci-2a)
Informal Assessment:
1. TTW listen to student responses to verbal questioning (M) regarding the parts of a chemical equation (C).
2. TTW observe responses to the chemical equation worksheet (M) regarding the parts of a chemical equation (C).
3. TTW observe student responses (M) aimed at generating and labeling an equation (C) for the demonstration performed in class.
Formal Assessment:
1. TSW take a short quiz at the end of class (M) including questions regarding the parts of a chemical equation (C).
2. TSW take a test at the end of the unit (M) The test will cover the parts of a chemical equation (C). The test will be graded and the grade recorded (D).
Objective:
TSW recognize the chemical equations for chemical respiration and photosynthesis. (DOK1, 8Sci-2a)
Informal Assessment:
1. TTW listen to student responses to verbal questioning (M) regarding the chemical equation for respiration and photosynthesis (C).
2. TTW observe the creation of an art project (M) depicting the chemical equations for photosynthesis and respiration (C).
Formal Assessment:
1. TSW take a short quiz at the end of class (M) including questions regarding the chemical equation for respiration and photosynthesis (C).
2. TSW take a test at the end of the unit (M) The test will cover the chemical equations for respiration and photosynthesis (C). The test will be graded and the grade recorded (D).