49 Balancing Chemical Equations Worksheets [with Answers] - Free Printable
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Step-by-step solution for: 49 Balancing Chemical Equations Worksheets [with Answers]
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Show Answer Key & Explanations
Step-by-step solution for: 49 Balancing Chemical Equations Worksheets [with Answers]
To balance the 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 with explanations:
---
- Start with the unbalanced equation: \( \text{N}_2 + \text{H}_2 \rightarrow \text{NH}_3 \)
- On the left side, there are 2 N atoms and 2 H atoms.
- On the right side, there is 1 N atom and 3 H atoms in one molecule of NH₃.
- To balance nitrogen (N), we need 2 NH₃ molecules on the right.
- To balance hydrogen (H), we need 3 H₂ molecules on the left.
- Balanced equation: \( \text{N}_2 + 3\text{H}_2 \rightarrow 2\text{NH}_3 \)
---
- Start with the unbalanced equation: \( \text{S}_8 + \text{O}_2 \rightarrow \text{SO}_3 \)
- On the left side, there are 8 S atoms and 2 O atoms.
- On the right side, there is 1 S atom and 3 O atoms in one molecule of SO₃.
- To balance sulfur (S), we need 8 SO₃ molecules on the right.
- To balance oxygen (O), we need 12 O₂ molecules on the left (since 8 × 3 = 24 O atoms).
- Balanced equation: \( \text{S}_8 + 12\text{O}_2 \rightarrow 8\text{SO}_3 \)
---
- Start with the unbalanced equation: \( \text{HgO} \rightarrow \text{Hg} + \text{O}_2 \)
- On the left side, there is 1 Hg atom and 1 O atom.
- On the right side, there is 1 Hg atom and 2 O atoms.
- To balance oxygen (O), we need 2 HgO molecules on the left.
- Balanced equation: \( 2\text{HgO} \rightarrow 2\text{Hg} + \text{O}_2 \)
---
- Start with the unbalanced equation: \( \text{Zn} + \text{HCl} \rightarrow \text{ZnCl}_2 + \text{H}_2 \)
- On the left side, there is 1 Zn atom, 1 H atom, and 1 Cl atom.
- On the right side, there is 1 Zn atom, 2 Cl atoms, and 2 H atoms.
- To balance chlorine (Cl), we need 2 HCl molecules on the left.
- Balanced equation: \( \text{Zn} + 2\text{HCl} \rightarrow \text{ZnCl}_2 + \text{H}_2 \)
---
- Start with the unbalanced equation: \( \text{SiCl}_4 + \text{H}_2\text{O} \rightarrow \text{H}_4\text{SiO}_4 + \text{HCl} \)
- On the left side, there is 1 Si atom, 4 Cl atoms, 2 H atoms, and 1 O atom.
- On the right side, there is 1 Si atom, 4 H atoms, 1 O atom, and 1 Cl atom.
- To balance chlorine (Cl), we need 4 HCl molecules on the right.
- To balance hydrogen (H), we need 4 H₂O molecules on the left.
- Balanced equation: \( \text{SiCl}_4 + 4\text{H}_2\text{O} \rightarrow \text{H}_4\text{SiO}_4 + 4\text{HCl} \)
---
- Start with the unbalanced equation: \( \text{Na} + \text{H}_2\text{O} \rightarrow \text{NaOH} + \text{H}_2 \)
- On the left side, there is 1 Na atom, 2 H atoms, and 1 O atom.
- On the right side, there is 1 Na atom, 3 H atoms, and 1 O atom.
- To balance hydrogen (H), we need 2 H₂O molecules on the left.
- To balance sodium (Na), we need 2 Na atoms on the left.
- Balanced equation: \( 2\text{Na} + 2\text{H}_2\text{O} \rightarrow 2\text{NaOH} + \text{H}_2 \)
---
- Start with the unbalanced equation: \( \text{H}_3\text{PO}_4 \rightarrow \text{H}_4\text{P}_2\text{O}_7 + \text{H}_2\text{O} \)
- On the left side, there are 3 H atoms, 1 P atom, and 4 O atoms.
- On the right side, there are 4 H atoms, 2 P atoms, and 7 O atoms.
- To balance phosphorus (P), we need 2 H₃PO₄ molecules on the left.
- To balance hydrogen (H), we need 3 H₂O molecules on the right.
- Balanced equation: \( 2\text{H}_3\text{PO}_4 \rightarrow \text{H}_4\text{P}_2\text{O}_7 + 3\text{H}_2\text{O} \)
---
- Start with the unbalanced equation: \( \text{Si}_2\text{H}_3 + \text{O}_2 \rightarrow \text{SiO}_2 + \text{H}_2\text{O} \)
- On the left side, there are 2 Si atoms, 3 H atoms, and 2 O atoms.
- On the right side, there are 2 Si atoms, 2 H atoms, and 4 O atoms.
- To balance hydrogen (H), we need 3/2 H₂O molecules on the right, but since we can't have fractional coefficients, multiply everything by 2.
- After multiplying, we have: \( 2\text{Si}_2\text{H}_3 + 5\text{O}_2 \rightarrow 4\text{SiO}_2 + 3\text{H}_2\text{O} \)
- Balanced equation: \( 2\text{Si}_2\text{H}_3 + 5\text{O}_2 \rightarrow 4\text{SiO}_2 + 3\text{H}_2\text{O} \)
---
- Start with the unbalanced equation: \( \text{Al(OH)}_3 + \text{H}_2\text{SO}_4 \rightarrow \text{Al}_2(\text{SO}_4)_3 + \text{H}_2\text{O} \)
- On the left side, there is 1 Al atom, 3 O atoms, 3 H atoms, and 1 S atom.
- On the right side, there are 2 Al atoms, 12 O atoms, 2 H atoms, and 3 S atoms.
- To balance aluminum (Al), we need 2 Al(OH)₃ molecules on the left.
- To balance sulfur (S), we need 3 H₂SO₄ molecules on the left.
- To balance hydrogen (H), we need 6 H₂O molecules on the right.
- Balanced equation: \( 2\text{Al(OH)}_3 + 3\text{H}_2\text{SO}_4 \rightarrow \text{Al}_2(\text{SO}_4)_3 + 6\text{H}_2\text{O} \)
---
- Start with the unbalanced equation: \( \text{Fe} + \text{O}_2 \rightarrow \text{Fe}_2\text{O}_3 \)
- On the left side, there is 1 Fe atom and 2 O atoms.
- On the right side, there are 2 Fe atoms and 3 O atoms.
- To balance iron (Fe), we need 2 Fe atoms on the left.
- To balance oxygen (O), we need 3/2 O₂ molecules on the right, but since we can't have fractional coefficients, multiply everything by 2.
- After multiplying, we have: \( 4\text{Fe} + 3\text{O}_2 \rightarrow 2\text{Fe}_2\text{O}_3 \)
- Balanced equation: \( 4\text{Fe} + 3\text{O}_2 \rightarrow 2\text{Fe}_2\text{O}_3 \)
---
- Start with the unbalanced equation: \( \text{Fe}_2(\text{SO}_4)_3 + \text{KOH} \rightarrow \text{K}_2\text{SO}_4 + \text{Fe(OH)}_3 \)
- On the left side, there are 2 Fe atoms, 3 S atoms, 12 O atoms, 1 K atom, and 1 H atom.
- On the right side, there are 2 Fe atoms, 1 S atom, 7 O atoms, 2 K atoms, and 3 H atoms.
- To balance potassium (K), we need 2 KOH molecules on the left.
- To balance sulfur (S), we need 3 K₂SO₄ molecules on the right.
- To balance hydrogen (H), we need 6 KOH molecules on the left.
- Balanced equation: \( \text{Fe}_2(\text{SO}_4)_3 + 6\text{KOH} \rightarrow 3\text{K}_2\text{SO}_4 + 2\text{Fe(OH)}_3 \)
---
- Start with the unbalanced equation: \( \text{FeS}_2 + \text{O}_2 \rightarrow \text{Fe}_2\text{O}_3 + \text{SO}_2 \)
- On the left side, there is 1 Fe atom, 2 S atoms, and 2 O atoms.
- On the right side, there are 2 Fe atoms, 1 S atom, 3 O atoms, and 2 O atoms in SO₂.
- To balance iron (Fe), we need 2 FeS₂ molecules on the left.
- To balance sulfur (S), we need 4 SO₂ molecules on the right.
- To balance oxygen (O), we need 11/2 O₂ molecules on the left, but since we can't have fractional coefficients, multiply everything by 2.
- After multiplying, we have: \( 4\text{FeS}_2 + 11\text{O}_2 \rightarrow 2\text{Fe}_2\text{O}_3 + 8\text{SO}_2 \)
- Balanced equation: \( 4\text{FeS}_2 + 11\text{O}_2 \rightarrow 2\text{Fe}_2\text{O}_3 + 8\text{SO}_2 \)
---
- Start with the unbalanced equation: \( \text{Al} + \text{FeO} \rightarrow \text{Al}_2\text{O}_3 + \text{Fe} \)
- On the left side, there is 1 Al atom, 1 Fe atom, and 1 O atom.
- On the right side, there are 2 Al atoms, 1 Fe atom, and 3 O atoms.
- To balance aluminum (Al), we need 2 Al atoms on the left.
- To balance oxygen (O), we need 3 FeO molecules on the left.
- To balance iron (Fe), we need 3 Fe atoms on the right.
- Balanced equation: \( 2\text{Al} + 3\text{FeO} \rightarrow \text{Al}_2\text{O}_3 + 3\text{Fe} \)
---
- Start with the unbalanced equation: \( \text{Na}_2\text{CO}_3 + \text{HCl} \rightarrow \text{NaCl} + \text{H}_2\text{O} + \text{CO}_2 \)
- On the left side, there are 2 Na atoms, 1 C atom, 3 O atoms, 1 H atom, and 1 Cl atom.
- On the right side, there are 1 Na atom, 1 C atom, 3 O atoms, 2 H atoms, and 1 Cl atom.
- To balance sodium (Na), we need 2 NaCl molecules on the right.
- To balance hydrogen (H), we need 2 HCl molecules on the left.
- Balanced equation: \( \text{Na}_2\text{CO}_3 + 2\text{HCl} \rightarrow 2\text{NaCl} + \text{H}_2\text{O} + \text{CO}_2 \)
---
- Start with the unbalanced equation: \( \text{K} + \text{Br}_2 \rightarrow \text{KBr} \)
- On the left side, there is 1 K atom and 2 Br atoms.
- On the right side, there is 1 K atom and 1 Br atom.
- To balance bromine (Br), we need 2 KBr molecules on the right.
- To balance potassium (K), we need 2 K atoms on the left.
- Balanced equation: \( 2\text{K} + \text{Br}_2 \rightarrow 2\text{KBr} \)
---
- Start with the unbalanced equation: \( \text{P}_4 + \text{O}_2 \rightarrow \text{P}_2\text{O}_5 \)
- On the left side, there are 4 P atoms and 2 O atoms.
- On the right side, there are 2 P atoms and 5 O atoms.
- To balance phosphorus (P), we need 2 P₂O₅ molecules on the right.
- To balance oxygen (O), we need 5 O₂ molecules on the left.
- Balanced equation: \( \text{P}_4 + 5\text{O}_2 \rightarrow 2\text{P}_2\text{O}_5 \)
---
- Start with the unbalanced equation: \( \text{C}_2\text{H}_2 + \text{O}_2 \rightarrow \text{CO}_2 + \text{H}_2\text{O} \)
- On the left side, there are 2 C atoms, 2 H atoms, and 2 O atoms.
- On the right side, there are 2 C atoms, 2 H atoms, and 3 O atoms.
- To balance oxygen (O), we need 3/2 O₂ molecules on the left, but since we can't have fractional coefficients, multiply everything by 2.
- After multiplying, we have: \( 2\text{C}_2\text{H}_2 + 5\text{O}_2 \rightarrow 4\text{CO}_2 + 2\text{H}_2\text{O} \)
- Balanced equation: \( 2\text{C}_2\text{H}_2 + 5\text{O}_2 \rightarrow 4\text{CO}_2 + 2\text{H}_2\text{O} \)
---
\[
\boxed{
\begin{aligned}
1. & \quad \text{N}_2 + 3\text{H}_2 \rightarrow 2\text{NH}_3 \\
2. & \quad \text{S}_8 + 12\text{O}_2 \rightarrow 8\text{SO}_3 \\
3. & \quad 2\text{HgO} \rightarrow 2\text{Hg} + \text{O}_2 \\
4. & \quad \text{Zn} + 2\text{HCl} \rightarrow \text{ZnCl}_2 + \text{H}_2 \\
5. & \quad \text{SiCl}_4 + 4\text{H}_2\text{O} \rightarrow \text{H}_4\text{SiO}_4 + 4\text{HCl} \\
6. & \quad 2\text{Na} + 2\text{H}_2\text{O} \rightarrow 2\text{NaOH} + \text{H}_2 \\
7. & \quad 2\text{H}_3\text{PO}_4 \rightarrow \text{H}_4\text{P}_2\text{O}_7 + 3\text{H}_2\text{O} \\
8. & \quad 2\text{Si}_2\text{H}_3 + 5\text{O}_2 \rightarrow 4\text{SiO}_2 + 3\text{H}_2\text{O} \\
9. & \quad 2\text{Al(OH)}_3 + 3\text{H}_2\text{SO}_4 \rightarrow \text{Al}_2(\text{SO}_4)_3 + 6\text{H}_2\text{O} \\
10. & \quad 4\text{Fe} + 3\text{O}_2 \rightarrow 2\text{Fe}_2\text{O}_3 \\
11. & \quad \text{Fe}_2(\text{SO}_4)_3 + 6\text{KOH} \rightarrow 3\text{K}_2\text{SO}_4 + 2\text{Fe(OH)}_3 \\
12. & \quad 4\text{FeS}_2 + 11\text{O}_2 \rightarrow 2\text{Fe}_2\text{O}_3 + 8\text{SO}_2 \\
13. & \quad 2\text{Al} + 3\text{FeO} \rightarrow \text{Al}_2\text{O}_3 + 3\text{Fe} \\
14. & \quad \text{Na}_2\text{CO}_3 + 2\text{HCl} \rightarrow 2\text{NaCl} + \text{H}_2\text{O} + \text{CO}_2 \\
15. & \quad 2\text{K} + \text{Br}_2 \rightarrow 2\text{KBr} \\
16. & \quad \text{P}_4 + 5\text{O}_2 \rightarrow 2\text{P}_2\text{O}_5 \\
17. & \quad 2\text{C}_2\text{H}_2 + 5\text{O}_2 \rightarrow 4\text{CO}_2 + 2\text{H}_2\text{O}
\end{aligned}
}
\]
---
1. \( \text{N}_2 + \text{H}_2 \rightarrow \text{NH}_3 \)
- Start with the unbalanced equation: \( \text{N}_2 + \text{H}_2 \rightarrow \text{NH}_3 \)
- On the left side, there are 2 N atoms and 2 H atoms.
- On the right side, there is 1 N atom and 3 H atoms in one molecule of NH₃.
- To balance nitrogen (N), we need 2 NH₃ molecules on the right.
- To balance hydrogen (H), we need 3 H₂ molecules on the left.
- Balanced equation: \( \text{N}_2 + 3\text{H}_2 \rightarrow 2\text{NH}_3 \)
---
2. \( \text{S}_8 + \text{O}_2 \rightarrow \text{SO}_3 \)
- Start with the unbalanced equation: \( \text{S}_8 + \text{O}_2 \rightarrow \text{SO}_3 \)
- On the left side, there are 8 S atoms and 2 O atoms.
- On the right side, there is 1 S atom and 3 O atoms in one molecule of SO₃.
- To balance sulfur (S), we need 8 SO₃ molecules on the right.
- To balance oxygen (O), we need 12 O₂ molecules on the left (since 8 × 3 = 24 O atoms).
- Balanced equation: \( \text{S}_8 + 12\text{O}_2 \rightarrow 8\text{SO}_3 \)
---
3. \( \text{HgO} \rightarrow \text{Hg} + \text{O}_2 \)
- Start with the unbalanced equation: \( \text{HgO} \rightarrow \text{Hg} + \text{O}_2 \)
- On the left side, there is 1 Hg atom and 1 O atom.
- On the right side, there is 1 Hg atom and 2 O atoms.
- To balance oxygen (O), we need 2 HgO molecules on the left.
- Balanced equation: \( 2\text{HgO} \rightarrow 2\text{Hg} + \text{O}_2 \)
---
4. \( \text{Zn} + \text{HCl} \rightarrow \text{ZnCl}_2 + \text{H}_2 \)
- Start with the unbalanced equation: \( \text{Zn} + \text{HCl} \rightarrow \text{ZnCl}_2 + \text{H}_2 \)
- On the left side, there is 1 Zn atom, 1 H atom, and 1 Cl atom.
- On the right side, there is 1 Zn atom, 2 Cl atoms, and 2 H atoms.
- To balance chlorine (Cl), we need 2 HCl molecules on the left.
- Balanced equation: \( \text{Zn} + 2\text{HCl} \rightarrow \text{ZnCl}_2 + \text{H}_2 \)
---
5. \( \text{SiCl}_4 + \text{H}_2\text{O} \rightarrow \text{H}_4\text{SiO}_4 + \text{HCl} \)
- Start with the unbalanced equation: \( \text{SiCl}_4 + \text{H}_2\text{O} \rightarrow \text{H}_4\text{SiO}_4 + \text{HCl} \)
- On the left side, there is 1 Si atom, 4 Cl atoms, 2 H atoms, and 1 O atom.
- On the right side, there is 1 Si atom, 4 H atoms, 1 O atom, and 1 Cl atom.
- To balance chlorine (Cl), we need 4 HCl molecules on the right.
- To balance hydrogen (H), we need 4 H₂O molecules on the left.
- Balanced equation: \( \text{SiCl}_4 + 4\text{H}_2\text{O} \rightarrow \text{H}_4\text{SiO}_4 + 4\text{HCl} \)
---
6. \( \text{Na} + \text{H}_2\text{O} \rightarrow \text{NaOH} + \text{H}_2 \)
- Start with the unbalanced equation: \( \text{Na} + \text{H}_2\text{O} \rightarrow \text{NaOH} + \text{H}_2 \)
- On the left side, there is 1 Na atom, 2 H atoms, and 1 O atom.
- On the right side, there is 1 Na atom, 3 H atoms, and 1 O atom.
- To balance hydrogen (H), we need 2 H₂O molecules on the left.
- To balance sodium (Na), we need 2 Na atoms on the left.
- Balanced equation: \( 2\text{Na} + 2\text{H}_2\text{O} \rightarrow 2\text{NaOH} + \text{H}_2 \)
---
7. \( \text{H}_3\text{PO}_4 \rightarrow \text{H}_4\text{P}_2\text{O}_7 + \text{H}_2\text{O} \)
- Start with the unbalanced equation: \( \text{H}_3\text{PO}_4 \rightarrow \text{H}_4\text{P}_2\text{O}_7 + \text{H}_2\text{O} \)
- On the left side, there are 3 H atoms, 1 P atom, and 4 O atoms.
- On the right side, there are 4 H atoms, 2 P atoms, and 7 O atoms.
- To balance phosphorus (P), we need 2 H₃PO₄ molecules on the left.
- To balance hydrogen (H), we need 3 H₂O molecules on the right.
- Balanced equation: \( 2\text{H}_3\text{PO}_4 \rightarrow \text{H}_4\text{P}_2\text{O}_7 + 3\text{H}_2\text{O} \)
---
8. \( \text{Si}_2\text{H}_3 + \text{O}_2 \rightarrow \text{SiO}_2 + \text{H}_2\text{O} \)
- Start with the unbalanced equation: \( \text{Si}_2\text{H}_3 + \text{O}_2 \rightarrow \text{SiO}_2 + \text{H}_2\text{O} \)
- On the left side, there are 2 Si atoms, 3 H atoms, and 2 O atoms.
- On the right side, there are 2 Si atoms, 2 H atoms, and 4 O atoms.
- To balance hydrogen (H), we need 3/2 H₂O molecules on the right, but since we can't have fractional coefficients, multiply everything by 2.
- After multiplying, we have: \( 2\text{Si}_2\text{H}_3 + 5\text{O}_2 \rightarrow 4\text{SiO}_2 + 3\text{H}_2\text{O} \)
- Balanced equation: \( 2\text{Si}_2\text{H}_3 + 5\text{O}_2 \rightarrow 4\text{SiO}_2 + 3\text{H}_2\text{O} \)
---
9. \( \text{Al(OH)}_3 + \text{H}_2\text{SO}_4 \rightarrow \text{Al}_2(\text{SO}_4)_3 + \text{H}_2\text{O} \)
- Start with the unbalanced equation: \( \text{Al(OH)}_3 + \text{H}_2\text{SO}_4 \rightarrow \text{Al}_2(\text{SO}_4)_3 + \text{H}_2\text{O} \)
- On the left side, there is 1 Al atom, 3 O atoms, 3 H atoms, and 1 S atom.
- On the right side, there are 2 Al atoms, 12 O atoms, 2 H atoms, and 3 S atoms.
- To balance aluminum (Al), we need 2 Al(OH)₃ molecules on the left.
- To balance sulfur (S), we need 3 H₂SO₄ molecules on the left.
- To balance hydrogen (H), we need 6 H₂O molecules on the right.
- Balanced equation: \( 2\text{Al(OH)}_3 + 3\text{H}_2\text{SO}_4 \rightarrow \text{Al}_2(\text{SO}_4)_3 + 6\text{H}_2\text{O} \)
---
10. \( \text{Fe} + \text{O}_2 \rightarrow \text{Fe}_2\text{O}_3 \)
- Start with the unbalanced equation: \( \text{Fe} + \text{O}_2 \rightarrow \text{Fe}_2\text{O}_3 \)
- On the left side, there is 1 Fe atom and 2 O atoms.
- On the right side, there are 2 Fe atoms and 3 O atoms.
- To balance iron (Fe), we need 2 Fe atoms on the left.
- To balance oxygen (O), we need 3/2 O₂ molecules on the right, but since we can't have fractional coefficients, multiply everything by 2.
- After multiplying, we have: \( 4\text{Fe} + 3\text{O}_2 \rightarrow 2\text{Fe}_2\text{O}_3 \)
- Balanced equation: \( 4\text{Fe} + 3\text{O}_2 \rightarrow 2\text{Fe}_2\text{O}_3 \)
---
11. \( \text{Fe}_2(\text{SO}_4)_3 + \text{KOH} \rightarrow \text{K}_2\text{SO}_4 + \text{Fe(OH)}_3 \)
- Start with the unbalanced equation: \( \text{Fe}_2(\text{SO}_4)_3 + \text{KOH} \rightarrow \text{K}_2\text{SO}_4 + \text{Fe(OH)}_3 \)
- On the left side, there are 2 Fe atoms, 3 S atoms, 12 O atoms, 1 K atom, and 1 H atom.
- On the right side, there are 2 Fe atoms, 1 S atom, 7 O atoms, 2 K atoms, and 3 H atoms.
- To balance potassium (K), we need 2 KOH molecules on the left.
- To balance sulfur (S), we need 3 K₂SO₄ molecules on the right.
- To balance hydrogen (H), we need 6 KOH molecules on the left.
- Balanced equation: \( \text{Fe}_2(\text{SO}_4)_3 + 6\text{KOH} \rightarrow 3\text{K}_2\text{SO}_4 + 2\text{Fe(OH)}_3 \)
---
12. \( \text{FeS}_2 + \text{O}_2 \rightarrow \text{Fe}_2\text{O}_3 + \text{SO}_2 \)
- Start with the unbalanced equation: \( \text{FeS}_2 + \text{O}_2 \rightarrow \text{Fe}_2\text{O}_3 + \text{SO}_2 \)
- On the left side, there is 1 Fe atom, 2 S atoms, and 2 O atoms.
- On the right side, there are 2 Fe atoms, 1 S atom, 3 O atoms, and 2 O atoms in SO₂.
- To balance iron (Fe), we need 2 FeS₂ molecules on the left.
- To balance sulfur (S), we need 4 SO₂ molecules on the right.
- To balance oxygen (O), we need 11/2 O₂ molecules on the left, but since we can't have fractional coefficients, multiply everything by 2.
- After multiplying, we have: \( 4\text{FeS}_2 + 11\text{O}_2 \rightarrow 2\text{Fe}_2\text{O}_3 + 8\text{SO}_2 \)
- Balanced equation: \( 4\text{FeS}_2 + 11\text{O}_2 \rightarrow 2\text{Fe}_2\text{O}_3 + 8\text{SO}_2 \)
---
13. \( \text{Al} + \text{FeO} \rightarrow \text{Al}_2\text{O}_3 + \text{Fe} \)
- Start with the unbalanced equation: \( \text{Al} + \text{FeO} \rightarrow \text{Al}_2\text{O}_3 + \text{Fe} \)
- On the left side, there is 1 Al atom, 1 Fe atom, and 1 O atom.
- On the right side, there are 2 Al atoms, 1 Fe atom, and 3 O atoms.
- To balance aluminum (Al), we need 2 Al atoms on the left.
- To balance oxygen (O), we need 3 FeO molecules on the left.
- To balance iron (Fe), we need 3 Fe atoms on the right.
- Balanced equation: \( 2\text{Al} + 3\text{FeO} \rightarrow \text{Al}_2\text{O}_3 + 3\text{Fe} \)
---
14. \( \text{Na}_2\text{CO}_3 + \text{HCl} \rightarrow \text{NaCl} + \text{H}_2\text{O} + \text{CO}_2 \)
- Start with the unbalanced equation: \( \text{Na}_2\text{CO}_3 + \text{HCl} \rightarrow \text{NaCl} + \text{H}_2\text{O} + \text{CO}_2 \)
- On the left side, there are 2 Na atoms, 1 C atom, 3 O atoms, 1 H atom, and 1 Cl atom.
- On the right side, there are 1 Na atom, 1 C atom, 3 O atoms, 2 H atoms, and 1 Cl atom.
- To balance sodium (Na), we need 2 NaCl molecules on the right.
- To balance hydrogen (H), we need 2 HCl molecules on the left.
- Balanced equation: \( \text{Na}_2\text{CO}_3 + 2\text{HCl} \rightarrow 2\text{NaCl} + \text{H}_2\text{O} + \text{CO}_2 \)
---
15. \( \text{K} + \text{Br}_2 \rightarrow \text{KBr} \)
- Start with the unbalanced equation: \( \text{K} + \text{Br}_2 \rightarrow \text{KBr} \)
- On the left side, there is 1 K atom and 2 Br atoms.
- On the right side, there is 1 K atom and 1 Br atom.
- To balance bromine (Br), we need 2 KBr molecules on the right.
- To balance potassium (K), we need 2 K atoms on the left.
- Balanced equation: \( 2\text{K} + \text{Br}_2 \rightarrow 2\text{KBr} \)
---
16. \( \text{P}_4 + \text{O}_2 \rightarrow \text{P}_2\text{O}_5 \)
- Start with the unbalanced equation: \( \text{P}_4 + \text{O}_2 \rightarrow \text{P}_2\text{O}_5 \)
- On the left side, there are 4 P atoms and 2 O atoms.
- On the right side, there are 2 P atoms and 5 O atoms.
- To balance phosphorus (P), we need 2 P₂O₅ molecules on the right.
- To balance oxygen (O), we need 5 O₂ molecules on the left.
- Balanced equation: \( \text{P}_4 + 5\text{O}_2 \rightarrow 2\text{P}_2\text{O}_5 \)
---
17. \( \text{C}_2\text{H}_2 + \text{O}_2 \rightarrow \text{CO}_2 + \text{H}_2\text{O} \)
- Start with the unbalanced equation: \( \text{C}_2\text{H}_2 + \text{O}_2 \rightarrow \text{CO}_2 + \text{H}_2\text{O} \)
- On the left side, there are 2 C atoms, 2 H atoms, and 2 O atoms.
- On the right side, there are 2 C atoms, 2 H atoms, and 3 O atoms.
- To balance oxygen (O), we need 3/2 O₂ molecules on the left, but since we can't have fractional coefficients, multiply everything by 2.
- After multiplying, we have: \( 2\text{C}_2\text{H}_2 + 5\text{O}_2 \rightarrow 4\text{CO}_2 + 2\text{H}_2\text{O} \)
- Balanced equation: \( 2\text{C}_2\text{H}_2 + 5\text{O}_2 \rightarrow 4\text{CO}_2 + 2\text{H}_2\text{O} \)
---
Final Answer:
\[
\boxed{
\begin{aligned}
1. & \quad \text{N}_2 + 3\text{H}_2 \rightarrow 2\text{NH}_3 \\
2. & \quad \text{S}_8 + 12\text{O}_2 \rightarrow 8\text{SO}_3 \\
3. & \quad 2\text{HgO} \rightarrow 2\text{Hg} + \text{O}_2 \\
4. & \quad \text{Zn} + 2\text{HCl} \rightarrow \text{ZnCl}_2 + \text{H}_2 \\
5. & \quad \text{SiCl}_4 + 4\text{H}_2\text{O} \rightarrow \text{H}_4\text{SiO}_4 + 4\text{HCl} \\
6. & \quad 2\text{Na} + 2\text{H}_2\text{O} \rightarrow 2\text{NaOH} + \text{H}_2 \\
7. & \quad 2\text{H}_3\text{PO}_4 \rightarrow \text{H}_4\text{P}_2\text{O}_7 + 3\text{H}_2\text{O} \\
8. & \quad 2\text{Si}_2\text{H}_3 + 5\text{O}_2 \rightarrow 4\text{SiO}_2 + 3\text{H}_2\text{O} \\
9. & \quad 2\text{Al(OH)}_3 + 3\text{H}_2\text{SO}_4 \rightarrow \text{Al}_2(\text{SO}_4)_3 + 6\text{H}_2\text{O} \\
10. & \quad 4\text{Fe} + 3\text{O}_2 \rightarrow 2\text{Fe}_2\text{O}_3 \\
11. & \quad \text{Fe}_2(\text{SO}_4)_3 + 6\text{KOH} \rightarrow 3\text{K}_2\text{SO}_4 + 2\text{Fe(OH)}_3 \\
12. & \quad 4\text{FeS}_2 + 11\text{O}_2 \rightarrow 2\text{Fe}_2\text{O}_3 + 8\text{SO}_2 \\
13. & \quad 2\text{Al} + 3\text{FeO} \rightarrow \text{Al}_2\text{O}_3 + 3\text{Fe} \\
14. & \quad \text{Na}_2\text{CO}_3 + 2\text{HCl} \rightarrow 2\text{NaCl} + \text{H}_2\text{O} + \text{CO}_2 \\
15. & \quad 2\text{K} + \text{Br}_2 \rightarrow 2\text{KBr} \\
16. & \quad \text{P}_4 + 5\text{O}_2 \rightarrow 2\text{P}_2\text{O}_5 \\
17. & \quad 2\text{C}_2\text{H}_2 + 5\text{O}_2 \rightarrow 4\text{CO}_2 + 2\text{H}_2\text{O}
\end{aligned}
}
\]
Parent Tip: Review the logic above to help your child master the concept of balancing equations worksheet answers chemistry.
