Question

Use the following picture to help you answer the question: What type of reaction is the examples provided below?

Synthesis Decomposition Single-Replacement Double-Replacement Combustion

Zn + 2HCl ⟶ ZnCl₂ + H₂
CH₄ + 2O₂ ⟶ CO₂ + 2H₂O + Heat
2H₂O₂ ⟶ 2H₂O + O₂
Na₂S + CaCl₂ ⟶ CaS + 2NaCl
N₂ + 3H₂ ⟶ 2NH₃

Answer 1

Based on the reactions provided, here’s the classification of each reaction type:

1. **Zn + 2HCl ⟶ ZnCl₂ + H₂** - This is a **Single-Replacement** reaction because zinc (Zn) replaces the hydrogen (H) in hydrochloric acid (HCl).

2. **CH₄ + 2O₂ ⟶ CO₂ + 2H₂O + Heat** - This is a **Combustion** reaction as it involves the burning of methane (CH₄) in oxygen (O₂), resulting in carbon dioxide (CO₂) and water (H₂O), and producing heat.

3. **2H₂O₂ ⟶ 2H₂O + O₂** - This is a **Decomposition** reaction as hydrogen peroxide (H₂O₂) breaks down into water (H₂O) and oxygen (O₂).

4. **Na₂S + CaCl₂ ⟶ CaS + 2NaCl** - This is a **Double-Replacement** reaction because the ions in sodium sulfide (Na₂S) and calcium chloride (CaCl₂) switch partners to form calcium sulfide (CaS) and sodium chloride (NaCl).

5. **N₂ + 3H₂ ⟶ 2NH₃** - This is a **Synthesis** reaction since nitrogen gas (N₂) and hydrogen gas (H₂) combine to form ammonia (NH₃).

Here's a summary of the types of reactions:

1. Single-Replacement
2. Combustion
3. Decomposition
4. Double-Replacement
5. Synthesis