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Yesterday, I showed them one way of learning Chemical reactions, today, we try another. . ACT ONE: Explanation of --> [] (dont care if it says middle school, it fits here just fine)

ACT TWO: Perform activity/demo

If the link is lost, I have copy/pasted it here.

** Balancing Chemical Equations Activity  ** by Liz LaRosa [|www.middleschoolscience.com] ** [|click here for a pdf version of pages 1, & 3] and [|page 2]  ** ** Updated Oct. 2007: Click here for activity cards ready to print in pdf format! [|Cards 1] & [|Cards 2] **

**Objectives** : **Materials:** These account for one complete set. Color scheme is **VERY** important for visualization during the activity. || **on 3x5 Index Cards** **Pre Lab Questions:** Answer the following before you begin the activity: || ** 5H2  ** > > ** Table 1 : Chemical Equations (whole page, large boxes, sideways into lab book) ** || **Make the following Equations on your desk** || **Reactants** || **Products** || **Reactants - Final** || **Products - Final** || **Balanced Equation** || > || **H2 + O2 --> H2O** ||  ||   ||   ||   ||   || > || **H2O2 --> H20 + O2** ||  ||   ||   ||   ||   || > || **Na + O2 --> Na2O** ||  ||   ||   ||   ||   || > || **N2 + H2 --> NH3** ||  ||   ||   ||   ||   || > || **P4 + O2 --> P4O10** ||  ||   ||   ||   ||   || > || **Fe + H2O --> Fe3O4 + H2** ||  ||   ||   ||   ||   || > || **C + H2 --> CH4** ||  ||   ||   ||   ||   || > || **Na2SO4 + CaCl2 -->** > **CaSO4 + NaCl** ||  ||   ||   ||   ||   || > || **C2H6 + O2 --> CO2 + H2O** ||  ||   ||   ||   ||   || > || **Al2O3 --> Al + O2** ||  ||   ||   ||   ||   || >
 * to read chemical equations
 * to identify elements by their chemical symbol
 * to count atoms
 * to identify the coefficients and subscripts in a chemical equation.
 * to label the reactants and products of a chemical equation
 * to balance chemical equations
 * **2 orange 6's ** || **1 red "Reactants" ** || **C O2 ** || ** Fe ** || ** N2 ** || ** Na2 S O4 ** ||
 * **4 red 2's ** || **2 black 7's** || **on 5x8 Index Cards** || **C H4 ** || ** Fe3 O4 ** || ** N H3 ** || ** O2 ** ||
 * **4 blue 3's ** || **2 blue "+" ** || ** Al ** || **C2 H6 ** || ** H2 ** || ** Na ** || ** P4 ** ||
 * **4 green 4's ** || **1 black "yield" sign --->** || ** Al2 O3 ** || ** Ca Cl2 ** || ** H2 O ** || ** Na Cl ** || ** P4 O10 ** ||
 * **2 purple 5's ** || **1 purple "Products" ** || **C** || ** Ca S O4 ** || ** H2 O2 ** || ** Na2 O ** || ||
 * # What number represents the **Coefficient**? _____
 * 1) What number represents the **Subscript**? _____
 * 2) What element is represented by the letter "**H**"? _____
 * 3) How many "**H**'s" do you have? _____ ||
 * Procedure : **
 * 1) Using your set of index cards, replicate the chemical equation onto your desk.
 * 2) Label the reactant side and the product side. **Record the following information into Table 1:**
 * 1) Identify the elements on the reactant side.
 * 2) Count the number of atoms for each element.
 * 3) Identify the elements on the product side.
 * 4) Count the number of atoms on the product side.
 * 5) Are the 2 sides equal? If not, the equation is not balanced.
 * 6) The index cards numbered 2 - 7 are your **coefficients**. They can **ONLY** be placed in front of the elements. You can **not** change the subscripts.
 * 7) Choose an element that is not balanced and begin to balance the equations.
 * 8) Continue until you have worked through all the elements.
 * 9) Once they are balance, count the final number of Reactants and Products.
 * 10) Write the balanced equation.
 * 11) Can your equation be simplified?
 * Data : **

**Conclusion**: 2-3 sentences on what you learned. **TEACHER NOTES:** Answers: [] The index cards are a bit time consuming to create. I had some students help at lunch time for a few days. Once done, you can laminate them and have them forever! The materials account for one complete set which is good for 2-3 students to use. Print activity cards on card stock instead of making index cards for quicker set up. The color coding is very important for visualization. It is easier and quicker to locate the elements that you are trying to balance. If everything is in black ink, its harder to distinguish the equation contents. I use this towards the end of my chemistry unit, its a great assessment tool because it involves a vast amount of abilities that were learned during the chemistry unit. I do the 1st two problems with the students to guide then through the procedure, and make sure they understand what is expected. This activity takes about 2 - 3 "45 minute" class periods. I follow up with a worksheet as a homework assignment.
 * Analysis/Results: **
 * 1) What does "-->" mean?
 * 2) What side of the equation are the reactants found? products?
 * 3) Why must all chemical equations be balanced?
 * 4) Why can't the subscripts be changed?
 * 5) What does it mean to "simplify" the equation?

© Copyright 2000, E. S. Belasic