Balancing equations worksheet featuring ten chemical reactions to balance.

Let's go through each chemical equation and balance them step by step. The goal is to ensure that the number of atoms of each element is the same on both sides of the equation.

---

1. C + O₂ → CO₂

- Left: 1 C, 2 O
- Right: 1 C, 2 O
✔ Already balanced.

Balanced equation:
C + O₂ → CO₂

---

2. H₂ + O₂ → H₂O

- Left: 2 H, 2 O
- Right: 2 H, 1 O → Not balanced

We need 2 O on the right → use 2 H₂O
Now right has: 4 H, 2 O
Left has: 2 H, 2 O → need 2 H₂

So:
2H₂ + O₂ → 2H₂O

✔ Balanced: 4 H, 2 O on both sides.

Balanced equation:
2H₂ + O₂ → 2H₂O

---

3. Na + H₂O → NaOH + H₂

- Left: 1 Na, 2 H, 1 O
- Right: 1 Na, 1 O, 1 H (in NaOH) + 2 H (in H₂) = 3 H → Not balanced

We need to balance H and O. Try 2 NaOH:

→ 2NaOH has 2 Na, 2 O, 2 H
But H₂ has 2 H → total H on right: 2 (from NaOH) + 2 (from H₂) = 4 H
So we need 2 H₂O on left → gives 4 H and 2 O

Now:
- Left: 2 Na? No — only 1 Na on left
Try 2 Na on left

So:
2Na + 2H₂O → 2NaOH + H₂

Check:
- Left: 2 Na, 4 H, 2 O
- Right: 2 Na, 2 O, 2 H (in 2NaOH) + 2 H (in H₂) = 4 H ✔

Wait! H₂ has 2 H, but we have 2 H from NaOH and 2 H from H₂ → total 4 H → correct

But H₂ molecule should be one molecule with 2 H atoms → so H₂ is fine.

Actually, we have:
- Right: 2NaOH → 2 Na, 2 O, 2 H
- H₂ → 2 H
Total: 2 Na, 2 O, 4 H

Left: 2Na + 2H₂O → 2 Na, 4 H, 2 O ✔

Balanced equation:
2Na + 2H₂O → 2NaOH + H₂

---

4. Na + O₂ → Na₂O

- Left: 1 Na, 2 O
- Right: 2 Na, 1 O → not balanced

Need 2 Na on left → 2Na
Right has 1 O, left has 2 O → need ½ O₂? But can't have fractions.

Multiply entire equation by 2:

Start over:
To get 2 Na on right → Na₂O → needs 2 Na on left
But O₂ has 2 O → Na₂O has only 1 O → need 2 Na₂O → 4 Na, 2 O

So:
- Right: 2 Na₂O → 4 Na, 2 O
- Left: O₂ → 2 O → good
- Need 4 Na on left

So:
4Na + O₂ → 2Na₂O

Check:
- Left: 4 Na, 2 O
- Right: 4 Na, 2 O ✔

Balanced equation:
4Na + O₂ → 2Na₂O

---

5. Na + Cl₂ → NaCl

- Left: 1 Na, 2 Cl
- Right: 1 Na, 1 Cl → not balanced

Need 2 NaCl → 2 Na, 2 Cl
So need 2 Na on left

2Na + Cl₂ → 2NaCl

✔ Balanced: 2 Na, 2 Cl on both sides

Balanced equation:
2Na + Cl₂ → 2NaCl

---

6. NaOH + HCl → NaCl + H₂O

- Left: Na, O, H (from NaOH), H and Cl (from HCl) → total: Na, O, 2H, Cl
- Right: Na, Cl, 2H, O → same

✔ Already balanced!

Balanced equation:
NaOH + HCl → NaCl + H₂O

---

7. NaOH + HNO₃ → NaNO₃ + H₂O

- Left: Na, O, H (from NaOH), H, N, O₃ (from HNO₃) → total: Na, N, 2H, 4O
- Right: Na, N, 3O (in NO₃), H₂O → 2H, 1O → total: Na, N, 2H, 4O ✔

Already balanced!

Balanced equation:
NaOH + HNO₃ → NaNO₃ + H₂O

---

8. NaOH + H₂SO₄ → Na₂SO₄ + H₂O

- Left: Na, O, H (from NaOH), H₂SO₄ → 2H, S, 4O → total: Na, 3H, S, 5O
- Right: Na₂SO₄ → 2Na, S, 4O; H₂O → 2H, 1O → total: 2Na, S, 5O, 2H → mismatch in Na and H

We need 2 Na on left → 2 NaOH
Then left: 2NaOH → 2Na, 2O, 2H; H₂SO₄ → 2H, S, 4O → total: 2Na, S, 4H, 6O

Right: Na₂SO₄ → 2Na, S, 4O; H₂O → 2H, 1O → total: 2Na, S, 2H, 5O → still not balanced

We need more water → try 2 H₂O

So:
2NaOH + H₂SO₄ → Na₂SO₄ + 2H₂O

Now check:
- Left: 2Na, 2O (from NaOH), 2H (from NaOH), plus H₂SO₄ → 2H, S, 4O → total: 2Na, S, 4H, 6O
- Right: Na₂SO₄ → 2Na, S, 4O; 2H₂O → 4H, 2O → total: 2Na, S, 4H, 6O ✔

Balanced equation:
2NaOH + H₂SO₄ → Na₂SO₄ + 2H₂O

---

9. Na₂CO₃ + HCl → NaCl + H₂O + CO₂

- Left: 2Na, C, 3O, H, Cl
- Right: Na, Cl, 2H, O, C, 2O → total: Na, Cl, 2H, 3O, C → mismatch

Need 2 NaCl → 2Na, 2Cl
So need 2 HCl on left

Now:
Na₂CO₃ + 2HCl → 2NaCl + H₂O + CO₂

Check:
- Left: Na₂CO₃ → 2Na, C, 3O; 2HCl → 2H, 2Cl → total: 2Na, C, 3O, 2H, 2Cl
- Right: 2NaCl → 2Na, 2Cl; H₂O → 2H, 1O; CO₂ → C, 2O → total: 2Na, 2Cl, 2H, 3O, C ✔

Balanced equation:
Na₂CO₃ + 2HCl → 2NaCl + H₂O + CO₂

---

10. NaOH + CO₂ → Na₂CO₃ + H₂O

- Left: Na, O, H, C, 2O → total: Na, C, 3O, H
- Right: Na₂CO₃ → 2Na, C, 3O; H₂O → 2H, 1O → total: 2Na, C, 4O, 2H → mismatch

Need 2 NaOH → 2Na, 2O, 2H

Try:
2NaOH + CO₂ → Na₂CO₃ + H₂O

Left: 2Na, 2O, 2H (from NaOH), CO₂ → C, 2O → total: 2Na, C, 4O, 2H
Right: Na₂CO₃ → 2Na, C, 3O; H₂O → 2H, 1O → total: 2Na, C, 4O, 2H ✔

Balanced equation:
2NaOH + CO₂ → Na₂CO₃ + H₂O

---

✔ Final Balanced Equations:

1. C + O₂ → CO₂
2. 2H₂ + O₂ → 2H₂O
3. 2Na + 2H₂O → 2NaOH + H₂
4. 4Na + O₂ → 2Na₂O
5. 2Na + Cl₂ → 2NaCl
6. NaOH + HCl → NaCl + H₂O
7. NaOH + HNO₃ → NaNO₃ + H₂O
8. 2NaOH + H₂SO₄ → Na₂SO₄ + 2H₂O
9. Na₂CO₃ + 2HCl → 2NaCl + H₂O + CO₂
10. 2NaOH + CO₂ → Na₂CO₃ + H₂O

All equations are now balanced! ✔