Transcription of Balancing Chemical Equations Using Models
1 Name: _____ Date: _____ Period: ____ Balancing Chemical Equations Using Models Objective Use Models as a means for Balancing Chemical Equations . Materials For each group of 4 students: Cup of Skittles 2 Paper Plates Procedure 1. Label one plate reactants and the other products, to represent each side of a Chemical equation. Use at least four different colors of skittles (representing atoms of different elements) to make Models of the substances in each equation below. 4 Skittles 2. Choose one color to represent an element in the following Chemical reaction. 3. To create a compound, put the correct color skittles together to represent a bond between the atoms. Ex: ___HCl + ____NaOH ____NaCl + ____H2O Na H Cl O + + NaOH HCl NaCl H2O 4.
2 Count the number of atoms you have total for your products and for your reactants, before you attempt to balance the equation. Look for the same colors on the products and reactants. Reactants Products Before Balancing After Balancing Before Balancing After Balancing Na 1 Na 1 O 1 O 1 H 2 H 2 Cl 1 Cl 1 Name: _____ Date: _____ Period: ____ 5. Determine if you need to balance the equation by adding coefficients, by comparing the numbers for each atom on the reactant side with the product side. ___HCl + ____NaOH ____NaCl + ____H2O Reactants Products Before Balancing After Balancing Before Balancing After Balancing Na 1 Na 1 O 1 O 1 H 2 H 2 Cl 1 Cl 1 6. Then add any coefficients if they are needed, and count how many atoms we now have. ___HCl + ____NaOH ____NaCl + ____H2O For our example we have the same number of each atom for both products and reactants, we do not need to add any coefficients to balance the equation.
3 Reactants Products Before Balancing After Balancing Before Balancing After Balancing Na 1 1 Na 1 1 O 1 1 O 1 1 H 2 2 H 2 2 Cl 1 1 Cl 1 1 Task: For each reaction below, use your Models to determine the products needed (if not already indicated), and then balance the equation. You will also need to indicate what kind of reaction is occurring: single replacement, double replacement, combustion, synthesis, or decomposition. a. ___H2 + ____Cl2 ____HCl Reactants Products Before Balancing After Balancing Before Balancing After Balancing Name: _____ Date: _____ Period: ____ b. ___ Mg + ___O2 ___MgO Reactants Products Before Balancing After Balancing Before Balancing After Balancing c. ___C2H6 + ___ O2 ___CO2 + ___H2O Reactants Products Before Balancing After Balancing Before Balancing After Balancing d.
4 ___KI + ___Br2 ___KBr + ___I2 Reactants Products Before Balancing After Balancing Before Balancing After Balancing e. ___H2CO3 ___CO2 + ___H2O Reactants Products Before Balancing After Balancing Before Balancing After Balancing Name: _____ Date: _____ Period: ____ f. ___Ca + ___H2O ___Ca(OH)2 + ___H2 Reactants Products Before Balancing After Balancing Before Balancing After Balancing g. ___KClO3 ___KCl + ___O2 Reactants Products Before Balancing After Balancing Before Balancing After Balancing h. ___CH4 + ___O2 ___CO2 + ___H2O Reactants Products Before Balancing After Balancing Before Balancing After Balancing For the next four reactions you will need to determine what the products will be and balance the equation.
5 I. ___Zn + ___HCl Reactants Products Before Balancing After Balancing Before Balancing After Balancing Name: _____ Date: _____ Period: ____ j. ___ C2H6 + ___ O2 Reactants Products Before Balancing After Balancing Before Balancing After Balancing k. ___C3H8 + ___O2 Reactants Products Before Balancing After Balancing Before Balancing After Balancing l. ___BaO + ___H2O Reactants Products Before Balancing After Balancing Before Balancing After Balancing Analysis 1. What side of the equation are the reactants found? products? 2. Why do we balance Chemical Equations ? 3. Why do we need the same amount of each atom on both the product and reactants sides?
6 4. Why can't the subscripts be changed?
