Chemical Reactions & Equations
1. What type of reaction is this: 2H₂ + O₂ → 2H₂O?
✅ Correct Answer: B) Combination Reaction
🔹 **Combination reaction** occurs when two or more reactants combine to form a single product.
**Explanation:**
- H₂ + O₂ combines to form H₂O, which is a classic example of a combination reaction.
2. Which reaction involves the breakdown of a compound into simpler substances?
✅ Correct Answer: C) Decomposition Reaction
🔹 **Decomposition reaction** occurs when a compound breaks down into two or more simpler substances.
**Example:**
- CaCO₃ → CaO + CO₂
- Calcium carbonate breaks down into calcium oxide and carbon dioxide.
3. What type of reaction is represented by the equation: Zn + CuSO₄ → ZnSO₄ + Cu?
✅ Correct Answer: B) Displacement Reaction
🔹 **Zinc displaces copper** from copper sulfate, forming zinc sulfate and copper.
**Explanation:**
- Zn + CuSO₄ → ZnSO₄ + Cu
- This is a displacement reaction as zinc is more reactive than copper.
4. What is the chemical formula of rust?
✅ Correct Answer: C) Fe₂O₃·xH₂O
🔹 Rust is **hydrated iron(III) oxide**.
**Explanation:**
- Rust forms due to the reaction of iron with oxygen and water.
5. What is the color of copper sulfate solution?
✅ Correct Answer: B) Blue
🔹 Copper sulfate solution is **blue** due to the presence of **Cu²⁺ ions**.
**Explanation:**
- Cu²⁺ ions give the solution its blue color.