CHEM 100 Santa Monica College Balancing Chemical Equations Questions

BALANCING CHEMICAL EQUATIONS
Load the simulation Balancing Chemical Equations
http://phet.colorado.edu/en/simulation/balancing-chemical-equations
CRITICAL THINKING QUESTIONS
Explore the Balancing Chemical Equations simulation.
a) What are the different ways that the simulation indicates when an equation is balanced?
For each balanced reaction, indicate the total number of molecules in the table below.
Reaction
Total Number of Molecules
Reactant Side
Product Side
(Left)
(Right)
Make Ammonia
Separate Water
Combust Methane
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.
For each balanced reaction, indicate the total number of atoms in the table below.
Reaction
Total Number of Atoms
Reactant Side
Product Side
(Left)
(Right)
Make Ammonia
Separate Water
Combust Methane
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?
What is the same on the left and right side of a balanced equation? Explain your answer.
Play level 1 of the balancing equation game. Write down the strategies you used to balance
chemical equations.
BALANCING CHEMICAL EQUATIONS
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Start level 2 of the balancing equation game using your strategies from Level 1, and adding new
strategies as needed.
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?
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
What do you have to do to the coefficients of equation I below to get to equation II?
i.
2 SnO2 + 4 H2 🡪 2 Sn + 4 H2O
ii.
SnO2 + 2 H2 🡪 Sn + 2 H2O
a) Both equation I and II are balanced, but is equation I the only correct way to write the
balanced equation?
b) Can you divide equation II by another factor and still have it be correct? Why or why not?
c) In a complete sentence, write down a method you could use to determine if an equation is
written in the correct way.
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BALANCING CHEMICAL EQUATIONS