10 questions based on the Physical Science Grade 12 Chemistry exam from November 2024:

Physical Science Grade 12 Chemistry:

1. **Which of the following molecules exhibits hydrogen bonding?**
   - A. HCl
   - B. NH₃
   - C. CO₂
   - D. CH₄

2. **Calculate the number of moles in 58 grams of NaCl.** (Molar mass of NaCl = 58.44 g/mol)

3. **Which of the following compounds is an example of a carboxylic acid?**
   - A. CH₃OH
   - B. CH₃COOH
   - C. CH₃CH₂OH
   - D. CH₄

4. **What is the empirical formula of a compound containing 40% carbon, 6.67% hydrogen, and 53.33% oxygen by mass?**

5. **Balance the following chemical equation: C₂H₆ + O₂ → CO₂ + H₂O.**

6. **Which of the following reactions is an example of a redox reaction?**
   - A. NaOH + HCl → NaCl + H₂O
   - B. Mg + O₂ → MgO
   - C. NH₃ + H₂SO₄ → (NH₄)₂SO₄
   - D. Ba(NO₃)₂ + Na₂SO₄ → BaSO₄ + 2NaNO₃

7. **Explain the difference between an ionic bond and a covalent bond. Provide examples of each.**

8. **Calculate the pH of a 0.01 M solution of HCl.**

9. **Describe the process of electrolysis and provide an example of a substance that can be decomposed by electrolysis.**

10. **Which of the following gases is produced when hydrochloric acid reacts with zinc?**
    - A. Oxygen
    - B. Nitrogen
    - C. Hydrogen
    - D. Carbon dioxide

These questions cover a range of topics within Grade 12 Chemistry, ensuring a comprehensive review. Happy studying!

Certainly! Here are the answers to the questions:

1. **Which of the following molecules exhibits hydrogen bonding?**
   - **Answer:** B. NH₃

2. **Calculate the number of moles in 58 grams of NaCl.** (Molar mass of NaCl = 58.44 g/mol)
   - **Answer:** 1 mole (since 58 g / 58.44 g/mol ≈ 1 mole)

3. **Which of the following compounds is an example of a carboxylic acid?**
   - **Answer:** B. CH₃COOH

4. **What is the empirical formula of a compound containing 40% carbon, 6.67% hydrogen, and 53.33% oxygen by mass?**
   - **Answer:** CH₂O

5. **Balance the following chemical equation: C₂H₆ + O₂ → CO₂ + H₂O.**
   - **Answer:** 2C₂H₆ + 7O₂ → 4CO₂ + 6H₂O

6. **Which of the following reactions is an example of a redox reaction?**
   - **Answer:** B. Mg + O₂ → MgO

7. **Explain the difference between an ionic bond and a covalent bond. Provide examples of each.**
   - **Answer:** An ionic bond is formed when one atom donates an electron to another atom, resulting in oppositely charged ions that attract each other (e.g., NaCl). A covalent bond is formed when two atoms share electrons (e.g., H₂O).

8. **Calculate the pH of a 0.01 M solution of HCl.**
   - **Answer:** pH = -log[H⁺] = -log(0.01) = 2

9. **Describe the process of electrolysis and provide an example of a substance that can be decomposed by electrolysis.**
   - **Answer:** Electrolysis is the process of using an electric current to drive a non-spontaneous chemical reaction. An example is the electrolysis of water (H₂O) to produce hydrogen gas (H₂) and oxygen gas (O₂).

10. **Which of the following gases is produced when hydrochloric acid reacts with zinc?**
    - **Answer:** C. Hydrogen

If you have any more questions or need further clarification on any of the answers, feel free to ask!