Balancing Chemical Equations

BALANCING CHEMICAL EQUATIONS CRITICAL THINKING QUESTIONS 1. Explore the Balancing Chemical Equations simulation by clicking the Introduction ti.e. Discuss with your group what you find. a) What are the different ways that the simulation indicates when an equation is balanced? The simulation indicates that an equation is balanced by showing a smiley face and equal sign rather than an unequal sign between the reactants and products or a smiley face and balanced scale between reactants and products. 2. For each balanced reaction, indicate the total number of molecules in the table below. Reaction Total Number of Molecules Reactant Side (Left) Product Side (Right) Make Ammonia 4 2 Separate Water 2 3 Combust Methane 3 3 3. Is the number of total molecules on the left side of a balanced equation always equal to the number of total molecules on the right side of the equation? Explain your answer. The total number of molecules on the left side of a balanced equation is not always equal to the number on the right side, because atoms can bond into molecules and group up differently on either side of the equation. 4. For each balanced reaction, indicate the total number of atoms in the table below. Reaction Make Ammonia Total Number of Atoms Reactant Side (Left) Product Side (Right) 8 8 Separate Water 6 6 Combust Methane 9 9 5. Is the number of total atoms on the left side of a balanced equation always equal to the number of total atoms on the right side of the equation? The total number of atoms on the left side of a balanced equation is always equal to the number of total atoms on the right side of the equation. This is because to be balanced there must be the same number of atoms of each element on each side of the equation. 6. What is the same on the left and right side of a balanced equation? Explain your answer. There are always the same elements and the same number of atoms of those elements on either side of the equation. This is because of the law of conservation of matter, where matter cannot be created or destroyed. Atoms are only rearranged. 7. As a group, play level 1 of the balancing equation game. Write down the strategies your group uses to balance chemical equations. In order to balance chemicals, the first step I always take is putting 1 down in front of each chemical. Then I see what elements still need evening out and continue to go back and forth between sides until the equation is balanced. 8. Start level 2 of the balancing equation game. Take turns in your group to balance the equations in the sim, using your strategies from Level 1, and adding new strategies as needed. Each person should be in charge of balancing at least one equation, asking for help from the group as needed. As a group, write down the equations as you solve them. CH4 + H2O 3H2 + CO CH4 + 4S CS2 + 2H2S 2C + 2H2O CH4 +CO2 2F2+ H2O OF2+ 2HF SO2+ 2H2 S + 2H2O During this level I also used the pictures and colors of the atoms to ensure that both sides are equal. 9. In the simulation, were you able to use noninteger numbers (like ½ or 0.43) for the coefficients in a balanced equation? Why do you think this is? I was not able to use non-integer numbers like decimals because atoms are the smallest unit of elements and cannot be split (aside from nuclear bombs). a) Which of the following are coefficients you could use in a balanced equation? ☐½ ☐¾ ☐1 ☐2 ☐6 ☐9 b) If you were balancing an equation containing the O2 molecule, which of the following would be correct representations of O2 and its coefficient? ☐ ½O2 ☐ O2 ☐ 3O2 ☐ 6O2 ☐ 3O ☐ 5O3 10. What do you have to do to the coefficients of equation I below to get to equation II? Which equation is the correct way to write a balanced equation? Why? i. 2 SnO2 + 4 H2 2 Sn + 4 H2O ii. SnO2 + 2 H2 Sn + 2 H2O In order to get from question one to question two you have to divide the coefficients by 2. Equation two is the correct way to write the balanced equation because the coefficients should be in terms of the lowest ones that balance the equation. 11. Start level 3 of the balancing equation game. Take turns and write down the equations as you solve them, along with any new strategies you needed for balancing. 4CO2+ 2H2O 2C2H2 +5O2 5N2+6H2O 4NH3 +6NO 2C2 + 7H6 4CO2+6H2O 4NH3+ 5O2 4NO+ 6H2O 2CO2+ 3H2OC2H5OH+3O2 I again used the colors and other strategies above to help me solve these equations. CHALLENGE QUESTIONS: BALANCE THE EQUATIONS BELOW. A. __2_ NaNO3 + ___ PbO ___ Pb(NO3)2 + ___ Na2O B. ___ Ca3P2 + __6_ H2O C. ___Fe2O3 + _3__ CO D. _4__NH3 + __7_ O2 __3_Ca(OH)2 + _2__ PH3 _2__Fe + _3__ CO2 __4_ NO2 + __6_ H2O E. __4_FeS + __7_O2 __2_Fe2O3 + _4__SO2 F. __2_ C3H6O2 + __7_ O2 _6__ CO2 + _6__ H2O