Educational worksheet on acids and bases, including matching definitions and identifying acidic or basic substances.

Here's the complete solution to the worksheet “What Do You Know About Acids and Bases?” with explanations.

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## ✔ Part 1: Matching

Match each term (1–10) with the correct definition (A–J).

| Letter | Term | Correct Match | Explanation |
|--------|---------------|---------------|-------------|
| 1 | Acid | B | An acid adds H⁺ ions (protons) to water. Example: HCl → H⁺ + Cl⁻ |
| 2 | Base | D | A base adds OH⁻ ions to water. Example: NaOH → Na⁺ + OH⁻ |
| 3 | Neutral | C | Neutral means equal H⁺ and OH⁻ ions — pure water is neutral (pH = 7). |
| 4 | Neutralize | A | Neutralization = acid + base → salt + water. They cancel each other out. |
| 5 | Acid Rain | E | Caused by pollution (SO₂, NOₓ), resulting in rain with pH < 5.6. |
| 6 | pH | F | pH measures acidity/basicity on a scale from 0–14. Lower = more acidic. |
| 7 | Salt Water | H | Salt water is the product of neutralization (e.g., HCl + NaOH → NaCl + H₂O). |
| 8 | Strong Acid | J | Strong acids completely dissociate in water, releasing many H⁺ ions (e.g., HCl, H₂SO₄). |
| 9 | Weak Base | G | Weak bases partially dissociate, adding only a few OH⁻ ions (e.g., NH₃). |
| 10 | Weak Acid | I | Weak acids partially dissociate, releasing few H⁺ ions (e.g., CH₃COOH, H₂CO₃). |

✔ Matching Answers:
1. B
2. D
3. C
4. A
5. E
6. F
7. H
8. J
9. G
10. I

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## ✔ Part 2: Is it an Acid or a Base?

> Instructions: Circle the acids and underline the bases.

🔵 Acids (Circle these):

These are substances that release H⁺ ions in water or have acidic properties.

- 11. HCl — Hydrochloric acid (strong acid)
- 13. H₃PO₄ — Phosphoric acid (weak acid)
- 17. H₂CO₃ — Carbonic acid (weak acid, found in soda)
- 20. HBr — Hydrobromic acid (strong acid)
- 21. H₂SO₄ — Sulfuric acid (strong acid)
- 23. apple juice — Contains malic/citric acid → acidic
- 24. lemonade — Contains citric acid → acidic
- 27. soft drinks — Contain carbonic/phosphoric acid → acidic

🟢 Bases (Underline these):

These are substances that release OH⁻ ions or have basic properties.

- 12. Mg(OH)₂ — Magnesium hydroxide (base, antacid)
- 14. KOH — Potassium hydroxide (strong base)
- 15. Ca(OH)₂ — Calcium hydroxide (base, limewater)
- 16. LiOH — Lithium hydroxide (strong base)
- 18. NaOH — Sodium hydroxide (strong base, lye)
- 19. Al(OH)₃ — Aluminum hydroxide (weak base, antacid)
- 25. soap — Basic (saponification reaction makes soap basic)
- 26. laundry detergent — Usually basic to break down grease/oils
- 28. bathroom cleaner — Often basic to dissolve soap scum/fats

⚠️ Special Case:

- 22. H₂O — Water is neutral, not an acid or base. *Leave it blank or mark as neutral if allowed.*

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## ✍️ Final Answer Summary:

Part 1: Matching

1. B
2. D
3. C
4. A
5. E
6. F
7. H
8. J
9. G
10. I

Part 2: Circle Acids / Underline Bases

CIRCLE (Acids):
11, 13, 17, 20, 21, 23, 24, 27

UNDERLINE (Bases):
12, 14, 15, 16, 18, 19, 25, 26, 28

Neutral (leave as-is):
22 (H₂O)

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