Balancing Chemical Equations interactive worksheet - Free Printable

To balance chemical equations, we need to ensure that the number of atoms of each element is the same on both sides of the equation. Here are the balanced equations for each problem, along with explanations:

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1. \( \_ \text{H}_2\text{O} \rightarrow \_ \text{H}_2 + \_ \text{O}_2 \)

- Initial Equation: \( \text{H}_2\text{O} \rightarrow \text{H}_2 + \text{O}_2 \)
- Analysis:
- Left side: 2 H atoms, 1 O atom
- Right side: 2 H atoms, 2 O atoms
- Balancing:
- To balance oxygen, we need 2 water molecules on the left.
- This gives us 4 H atoms and 2 O atoms on the left.
- To balance hydrogen, we need 2 H₂ molecules on the right.
- The equation becomes: \( 2\text{H}_2\text{O} \rightarrow 2\text{H}_2 + \text{O}_2 \)

Balanced Equation: \( 2\text{H}_2\text{O} \rightarrow 2\text{H}_2 + \text{O}_2 \)

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2. \( \_ \text{Fe}_2\text{O}_3 \rightarrow \_ \text{Fe} + \_ \text{O}_2 \)

- Initial Equation: \( \text{Fe}_2\text{O}_3 \rightarrow \text{Fe} + \text{O}_2 \)
- Analysis:
- Left side: 2 Fe atoms, 3 O atoms
- Right side: 1 Fe atom, 2 O atoms
- Balancing:
- To balance iron, we need 2 Fe atoms on the right.
- To balance oxygen, we need \( \frac{3}{2} \) O₂ molecules, but since coefficients must be whole numbers, we multiply everything by 2.
- The equation becomes: \( 2\text{Fe}_2\text{O}_3 \rightarrow 4\text{Fe} + 3\text{O}_2 \)

Balanced Equation: \( 2\text{Fe}_2\text{O}_3 \rightarrow 4\text{Fe} + 3\text{O}_2 \)

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3. \( \_ \text{Na} + \_ \text{Cl}_2 \rightarrow \_ \text{NaCl} \)

- Initial Equation: \( \text{Na} + \text{Cl}_2 \rightarrow \text{NaCl} \)
- Analysis:
- Left side: 1 Na atom, 2 Cl atoms
- Right side: 1 Na atom, 1 Cl atom
- Balancing:
- To balance chlorine, we need 2 NaCl molecules on the right.
- To balance sodium, we need 2 Na atoms on the left.
- The equation becomes: \( 2\text{Na} + \text{Cl}_2 \rightarrow 2\text{NaCl} \)

Balanced Equation: \( 2\text{Na} + \text{Cl}_2 \rightarrow 2\text{NaCl} \)

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4. \( \_ \text{HgO} \rightarrow \_ \text{Hg} + \_ \text{O}_2 \)

- Initial Equation: \( \text{HgO} \rightarrow \text{Hg} + \text{O}_2 \)
- Analysis:
- Left side: 1 Hg atom, 1 O atom
- Right side: 1 Hg atom, 2 O atoms
- Balancing:
- To balance oxygen, we need 2 HgO molecules on the left.
- This gives us 2 Hg atoms and 2 O atoms on the left.
- The equation becomes: \( 2\text{HgO} \rightarrow 2\text{Hg} + \text{O}_2 \)

Balanced Equation: \( 2\text{HgO} \rightarrow 2\text{Hg} + \text{O}_2 \)

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5. \( \_ \text{TiCl}_4 + \_ \text{O}_2 \rightarrow \_ \text{TiO}_2 + \_ \text{Cl}_2 \)

- Initial Equation: \( \text{TiCl}_4 + \text{O}_2 \rightarrow \text{TiO}_2 + \text{Cl}_2 \)
- Analysis:
- Left side: 1 Ti atom, 4 Cl atoms, 2 O atoms
- Right side: 1 Ti atom, 2 Cl atoms, 2 O atoms
- Balancing:
- Chlorine is already balanced (4 Cl atoms on both sides).
- Oxygen is already balanced (2 O atoms on both sides).
- Titanium is already balanced (1 Ti atom on both sides).

Balanced Equation: \( \text{TiCl}_4 + \text{O}_2 \rightarrow \text{TiO}_2 + 2\text{Cl}_2 \)

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6. \( \_ \text{Al} + \_ \text{O}_2 \rightarrow \_ \text{Al}_2\text{O}_3 \)

- Initial Equation: \( \text{Al} + \text{O}_2 \rightarrow \text{Al}_2\text{O}_3 \)
- Analysis:
- Left side: 1 Al atom, 2 O atoms
- Right side: 2 Al atoms, 3 O atoms
- Balancing:
- To balance aluminum, we need 2 Al atoms on the left.
- To balance oxygen, we need \( \frac{3}{2} \) O₂ molecules, but since coefficients must be whole numbers, we multiply everything by 2.
- The equation becomes: \( 4\text{Al} + 3\text{O}_2 \rightarrow 2\text{Al}_2\text{O}_3 \)

Balanced Equation: \( 4\text{Al} + 3\text{O}_2 \rightarrow 2\text{Al}_2\text{O}_3 \)

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7. \( \_ \text{HCl} + \_ \text{Zn} \rightarrow \_ \text{H}_2 + \_ \text{ZnCl}_2 \)

- Initial Equation: \( \text{HCl} + \text{Zn} \rightarrow \text{H}_2 + \text{ZnCl}_2 \)
- Analysis:
- Left side: 1 H atom, 1 Cl atom, 1 Zn atom
- Right side: 2 H atoms, 2 Cl atoms, 1 Zn atom
- Balancing:
- To balance hydrogen, we need 2 HCl molecules on the left.
- To balance chlorine, we need 2 Cl atoms on the right, which is already satisfied.
- The equation becomes: \( 2\text{HCl} + \text{Zn} \rightarrow \text{H}_2 + \text{ZnCl}_2 \)

Balanced Equation: \( 2\text{HCl} + \text{Zn} \rightarrow \text{H}_2 + \text{ZnCl}_2 \)

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8. \( \_ \text{Al} + \_ \text{CuCl}_2 \rightarrow \_ \text{AlCl}_3 + \_ \text{Cu} \)

- Initial Equation: \( \text{Al} + \text{CuCl}_2 \rightarrow \text{AlCl}_3 + \text{Cu} \)
- Analysis:
- Left side: 1 Al atom, 1 Cu atom, 2 Cl atoms
- Right side: 1 Al atom, 1 Cu atom, 3 Cl atoms
- Balancing:
- To balance chlorine, we need 3 CuCl₂ molecules on the left.
- This gives us 3 Cu atoms and 6 Cl atoms on the left.
- To balance aluminum, we need 2 Al atoms on the left.
- The equation becomes: \( 2\text{Al} + 3\text{CuCl}_2 \rightarrow 2\text{AlCl}_3 + 3\text{Cu} \)

Balanced Equation: \( 2\text{Al} + 3\text{CuCl}_2 \rightarrow 2\text{AlCl}_3 + 3\text{Cu} \)

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Final Answer

\[
\boxed{
\begin{aligned}
1. & \quad 2\text{H}_2\text{O} \rightarrow 2\text{H}_2 + \text{O}_2 \\
2. & \quad 2\text{Fe}_2\text{O}_3 \rightarrow 4\text{Fe} + 3\text{O}_2 \\
3. & \quad 2\text{Na} + \text{Cl}_2 \rightarrow 2\text{NaCl} \\
4. & \quad 2\text{HgO} \rightarrow 2\text{Hg} + \text{O}_2 \\
5. & \quad \text{TiCl}_4 + \text{O}_2 \rightarrow \text{TiO}_2 + 2\text{Cl}_2 \\
6. & \quad 4\text{Al} + 3\text{O}_2 \rightarrow 2\text{Al}_2\text{O}_3 \\
7. & \quad 2\text{HCl} + \text{Zn} \rightarrow \text{H}_2 + \text{ZnCl}_2 \\
8. & \quad 2\text{Al} + 3\text{CuCl}_2 \rightarrow 2\text{AlCl}_3 + 3\text{Cu}
\end{aligned}
}
\]