C.8D: Chemical Equations
Bonding and Chemical Reactions
Activity Description:
Students will be able to create balanced equations and understand the conservation of mass.
Materials:
1 Attachment: Student Lab Sheet (1 per student)
1 Set of colored paperclips* in a resealable baggie (1 per group of four students)
1 Pencil or pen (1 per student)
*Set of paperclips include: 15 red, 15 yellow, 15 blue, 15 green, 15 black, and 15 silver
paperclips. If paperclips are not available, interlocking blocks can be used, such as Legos.
Procedure:
Prepare materials for the students in advance. Print Student Lab Sheets for each student
and place paperclips in a resealable baggies. Each group of students should have a
resealable baggie containing the paperclips. Each student should be given a Student Lab
Sheet.
1. Give each group of students a resealable baggie with paperclips.
2. Give each student a Student Lab Sheet.
Explain to the students that each paperclip represents an element. Different elements
are represents by different colors. For example, H2O will be created using by clipping
together two red paperclips for hydrogen and one yellow paperclip for oxygen.
3. Students will use the paperclips to assemble compounds, molecules, or elements. Each
paperclip represents an atom.
Explain to students that they should create several of each compound, molecule, or
element. Explain that when balancing equations, the entire compound must be added,
not just the needed element of that compound or molecule.
4. Students balance the equations using the paperclips and place their answers on the Student
Lab Sheet.
5. Once the students complete their Student Lab Sheet, students should place the paperclips back
into the resealable baggie and return them.
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C.8D: Chemical Equations
Bonding and Chemical Reactions
Teacher Attachment: Student Lab Sheet (Key)
Directions: Balance the equations by placing the correct coefficient in front of each element,
molecule, or compound.
Key to paperclip colors:
Hydrogen = Red
Iron = Blue
Oxygen = Yellow
Sodium = Black
Chlorine = Green
Aluminum = Silver
1. 
___1____ FeCl3 + _____3___ NaOH  ___1_____ Fe(OH)3 + ____3____ NaCl
2. 
____1____ Na2O + ____1____ H2O  ____2____ NaOH
3. 
____4_____ Al + ____3_____ O2  ____2_____ Al2O3
4. 
____2_____ Al + ___6_____ HCl  ___3_____ H2 + ____2_____ AlCl3
5. 
____2_____ H2 + ___1_____ O2  ____2____ H2O
6. 
___4______ Fe + ____3_____ O2  _____2____ Fe2O3
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C.8D: Chemical Equations
Bonding and Chemical Reactions
Teacher Attachment: Student Lab Sheet (Key)
Directions: Complete the questions.
1.
Which number can be added within a chemical equation – coefficient or subscript?
Coefficient
2.
Which number cannot be added or subtracted within an equation – coefficient or
subscript?
Subscript
3. 
Which side of the equation is the location of the reactants?
Left
4. 
What does the  mean?
Yields or makes
Conclusion
1.
How does a balanced equation show the conservation of mass?
A balanced equation show how mass is conserved because the amount of each element
on the reactant side is the same amount of each element that is on the product side.
2. 
Explain what the parentheses mean in a chemical reaction, and how they are used (see the
first equation that needed balancing.)
The parentheses are placed around polyatomic ions to keep them grouped together. The
subscript after the parentheses tells how many of those polyatomic ions there are in the
formula. This is necessary to know when balancing the equation to guarantee that mass is
conserved.
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C.8D: Chemical Equations
Bonding and Chemical Reactions
Student Lab Sheet
Directions: Balance the equations by placing the correct coefficient in front of each element,
molecule, or compound.
Key to paperclip colors:
Hydrogen = Red
Iron = Blue
Oxygen = Yellow
Sodium = Black
Chlorine = Green
Aluminum = Silver
1. 
________ FeCl3 + ________ NaOH  ________ Fe(OH)3 + ________ NaCl
2. 
________ Na2O + ________ H2O  ________ NaOH
3. 
_________ Al + _________ O2  _________ Al2O3
4. 
_________ Al + ________ HCl  ________ H2 + _________ AlCl3
5. 
_________ H2 + ________ O2  ________ H2O
6. 
_________ Fe + _________ O2  _________ Fe2O3
1
C.8D: Chemical Equations
Bonding and Chemical Reactions
Student Lab Sheet
Directions: Complete the questions.
1. Which number can be added within a chemical equation – coefficient or subscript?
2. Which number cannot be added or subtracted within an equation – coefficient or subscript?
3. Which side of the equation is the location of the reactants?
4. What does the  mean?
Conclusion
1.
How does a balanced equation show the conservation of mass?
2.
Explain what the parentheses mean in a chemical reaction, and how they are used (see the
first equation that needed balancing.)
2