Question

Label the oxidation numbers on each element (replace red X with oxidation number)
Identify what was oxidized/reduced
Identify the type of reaction

Zn + 2HCl → ZnCl2 + H2

Oxidized:

Reduced:
What type of reaction is this?


Cu + 2 AgNO3 → 2 Ag + Cu(NO3)2


Oxidized:

Reduced:
What type of reaction is this?

2 Na + Cl2 → 2 NaCl

Oxidized:

Reduced:
What type of reaction is this?

Answer 1

Let's analyze each reaction step by step, determining the oxidation numbers for each element, identifying what was oxidized/reduced, and classifying the type of reaction.

### Reaction 1: Zn + 2HCl → ZnCl2 + H2

**Oxidation Numbers:**
- Zn: 0 (as a pure element)
- H in HCl: +1
- Cl in HCl: -1
- Zn in ZnCl2: +2
- Cl in ZnCl2: -1
- H in H2: 0 (as a pure element)

**Identifying Oxidation and Reduction:**
- **Oxidized:** Zn (goes from 0 to +2)
- **Reduced:** H+ (in HCl goes from +1 to 0)

**Type of Reaction:** This is a **single displacement reaction** (or single replacement reaction).

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### Reaction 2: Cu + 2 AgNO3 → 2 Ag + Cu(NO3)2

**Oxidation Numbers:**
- Cu: 0 (as a pure element)
- Ag in AgNO3: +1
- N in NO3: +5
- O in NO3: -2
- Cu in Cu(NO3)2: +2
- Ag: 0 (as a pure element)

**Identifying Oxidation and Reduction:**
- **Oxidized:** Cu (goes from 0 to +2)
- **Reduced:** Ag+ (goes from +1 to 0)

**Type of Reaction:** This is also a **single displacement reaction** (or single replacement reaction).

---

### Reaction 3: 2 Na + Cl2 → 2 NaCl

**Oxidation Numbers:**
- Na: 0 (as a pure element)
- Cl in Cl2: 0 (as a pure element)
- Na in NaCl: +1
- Cl in NaCl: -1

**Identifying Oxidation and Reduction:**
- **Oxidized:** Na (goes from 0 to +1)
- **Reduced:** Cl (goes from 0 to -1)

**Type of Reaction:** This is a **combination reaction** (also known as a synthesis reaction).

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### Summary

1. **Zn + 2HCl → ZnCl2 + H2**
- **Oxidized:** Zn
- **Reduced:** H+
- **Type of Reaction:** Single displacement

2. **Cu + 2 AgNO3 → 2 Ag + Cu(NO3)2**
- **Oxidized:** Cu
- **Reduced:** Ag+
- **Type of Reaction:** Single displacement

3. **2 Na + Cl2 → 2 NaCl**
- **Oxidized:** Na
- **Reduced:** Cl
- **Type of Reaction:** Combination (synthesis)