Balancing Equations Worksheet Answers 1-20 Explained
Table of Contents :
Balancing chemical equations is a fundamental concept in chemistry that allows us to represent chemical reactions accurately. For those just getting started or reviewing, worksheets that involve balancing equations can be immensely helpful. In this article, we will explore the answers to a Balancing Equations Worksheet, specifically questions 1 through 20. We will break down each equation, providing explanations for how to balance them correctly. ⚗️
Understanding Chemical Equations
A chemical equation represents a chemical reaction. It shows the reactants on the left and the products on the right, separated by an arrow that indicates the direction of the reaction. For a balanced equation, the number of atoms for each element must be the same on both sides of the equation. This is governed by the Law of Conservation of Mass, which states that matter cannot be created or destroyed in a chemical reaction.
Tips for Balancing Equations
Before we dive into the worksheet answers, let’s review some tips that can help you when balancing equations:
- Count Atoms: Begin by counting the number of atoms of each element in both the reactants and products.
- Use Coefficients: Adjust the coefficients (the numbers placed before the compounds) to change the number of molecules of a substance, rather than changing the subscripts (the numbers in a chemical formula).
- Start with Complex Molecules: It can be easier to start balancing more complex molecules before moving to simpler ones.
- Check Your Work: After balancing, recount the atoms on both sides to ensure they are equal.
Worksheet Answers 1-20 Explained
Now, let’s go through each equation on the worksheet and provide a detailed explanation of how to balance them. Here is a summary table of the original equations and their balanced forms.
<table> <tr> <th>Equation #</th> <th>Unbalanced Equation</th> <th>Balanced Equation</th> </tr> <tr> <td>1</td> <td>H₂ + O₂ → H₂O</td> <td>2 H₂ + O₂ → 2 H₂O</td> </tr> <tr> <td>2</td> <td>C + O₂ → CO₂</td> <td>C + O₂ → CO₂</td> </tr> <tr> <td>3</td> <td>Na + Cl₂ → NaCl</td> <td>2 Na + Cl₂ → 2 NaCl</td> </tr> <tr> <td>4</td> <td>Fe + O₂ → Fe₂O₃</td> <td>4 Fe + 3 O₂ → 2 Fe₂O₃</td> </tr> <tr> <td>5</td> <td>Ca + H₂O → Ca(OH)₂ + H₂</td> <td>Ca + 2 H₂O → Ca(OH)₂ + H₂</td> </tr> <tr> <td>6</td> <td>Al + O₂ → Al₂O₃</td> <td>4 Al + 3 O₂ → 2 Al₂O₃</td> </tr> <tr> <td>7</td> <td>C₃H₈ + O₂ → CO₂ + H₂O</td> <td>C₃H₈ + 5 O₂ → 3 CO₂ + 4 H₂O</td> </tr> <tr> <td>8</td> <td>Mg + HCl → MgCl₂ + H₂</td> <td>Mg + 2 HCl → MgCl₂ + H₂</td> </tr> <tr> <td>9</td> <td>NH₃ + O₂ → NO + H₂O</td> <td>4 NH₃ + 3 O₂ → 2 NO + 6 H₂O</td> </tr> <tr> <td>10</td> <td>H₂ + N₂ → NH₃</td> <td>3 H₂ + N₂ → 2 NH₃</td> </tr> <tr> <td>11</td> <td>Pb(NO₃)₂ + KI → PbI₂ + KNO₃</td> <td>1 Pb(NO₃)₂ + 2 KI → 1 PbI₂ + 2 KNO₃</td> </tr> <tr> <td>12</td> <td>NaOH + H₂SO₄ → Na₂SO₄ + H₂O</td> <td>2 NaOH + H₂SO₄ → Na₂SO₄ + 2 H₂O</td> </tr> <tr> <td>13</td> <td>K + H₂O → KOH + H₂</td> <td>2 K + 2 H₂O → 2 KOH + H₂</td> </tr> <tr> <td>14</td> <td>C₄H₁₀ + O₂ → CO₂ + H₂O</td> <td>C₄H₁₀ + 5 O₂ → 4 CO₂ + 5 H₂O</td> </tr> <tr> <td>15</td> <td>Cr + HCl → CrCl₃ + H₂</td> <td>2 Cr + 6 HCl → 2 CrCl₃ + 3 H₂</td> </tr> <tr> <td>16</td> <td>Zn + HCl → ZnCl₂ + H₂</td> <td>Zn + 2 HCl → ZnCl₂ + H₂</td> </tr> <tr> <td>17</td> <td>SO₂ + O₂ → SO₃</td> <td>2 SO₂ + O₂ → 2 SO₃</td> </tr> <tr> <td>18</td> <td>H₂ + F₂ → HF</td> <td>H₂ + F₂ → 2 HF</td> </tr> <tr> <td>19</td> <td>Li + O₂ → Li₂O</td> <td>4 Li + O₂ → 2 Li₂O</td> </tr> <tr> <td>20</td> <td>CH₄ + O₂ → CO + H₂O</td> <td>2 CH₄ + 3 O₂ → 2 CO + 4 H₂O</td> </tr> </table>
Breakdown of Each Equation
Equation 1: (H₂ + O₂ → H₂O)
To balance this, we see that there are 2 hydrogen atoms in (H₂) and only 1 in (H₂O). Therefore, we place a coefficient of 2 before (H₂O) and adjust (H₂) to 2 as well.
Equation 2: (C + O₂ → CO₂)
This equation is already balanced with 1 carbon and 2 oxygen on both sides.
Equation 3: (Na + Cl₂ → NaCl)
Sodium (Na) is balanced at 1, but chlorine (Cl) needs a coefficient of 2.
Equation 4: (Fe + O₂ → Fe₂O₃)
Iron (Fe) is balanced by placing a coefficient of 4 before (Fe) and 3 before (O₂).
Equation 5: (Ca + H₂O → Ca(OH)₂ + H₂)
We need 2 water molecules to balance the hydrogen, leading to a coefficient of 2 for (H₂O).
Equation 6: (Al + O₂ → Al₂O₃)
Four aluminum and three oxygen balance the equation correctly.
Equation 7: (C₃H₈ + O₂ → CO₂ + H₂O)
Balancing propane with coefficients gives us 3 CO₂ and 4 H₂O, requiring 5 oxygen.
Equation 8: (Mg + HCl → MgCl₂ + H₂)
The coefficient of 2 for (HCl) balances the reaction.
Equation 9: (NH₃ + O₂ → NO + H₂O)
Balancing this involves adjusting the coefficients to 4 and 3, respectively.
Equation 10: (H₂ + N₂ → NH₃)
This equation is balanced with 3 (H₂) and 1 (N₂).
Equation 11: (Pb(NO₃)₂ + KI → PbI₂ + KNO₃)
The coefficients balance perfectly as written.
Equation 12: (NaOH + H₂SO₄ → Na₂SO₄ + H₂O)
To balance sodium and sulfate, we need 2 (NaOH).
Equation 13: (K + H₂O → KOH + H₂)
A coefficient of 2 balances potassium and hydrogen.
Equation 14: (C₄H₁₀ + O₂ → CO₂ + H₂O)
This equation requires coefficients of 5 for oxygen.
Equation 15: (Cr + HCl → CrCl₃ + H₂)
This is balanced by using coefficients of 2 for chromium and 6 for hydrochloric acid.
Equation 16: (Zn + HCl → ZnCl₂ + H₂)
We balance with a coefficient of 2 for hydrochloric acid.
Equation 17: (SO₂ + O₂ → SO₃)
Balancing sulfur requires a coefficient of 2 for (SO₂).
Equation 18: (H₂ + F₂ → HF)
This is balanced as shown, requiring just 1 for each hydrogen and fluorine.
Equation 19: (Li + O₂ → Li₂O)
Four lithium atoms balance the equation with two lithium oxide molecules.
Equation 20: (CH₄ + O₂ → CO + H₂O)
A coefficient of 2 for both (CH₄) and (O₂) gives us a balanced equation.
Conclusion
Balancing equations may seem daunting at first, but with practice, it becomes much easier! The key is to carefully count atoms, make adjustments, and verify your work. Worksheets like the one we reviewed here provide a great opportunity to refine your skills and deepen your understanding of chemical reactions. Keep practicing, and you’ll soon find yourself balancing equations with ease! 🔬