Question

identify the oxidation-reduction reactions among the following:

1. zn(s) + cu²⁺(aq) → zn²⁺(aq) + cu(s)
2. 2 na(s) + cl₂(aq) → 2 nacl(s)
3. 2 mg(s) + o₂(g) → 2 mgo

○ a. 1 and 2 only
○ b. 1 and 3 only
○ c. 2 and 3 only
○ d. all of 1, 2, and 3
○ e. none of 1, 2, and 3

Explanation:

Step1: Analyze Reaction 1

In \( \text{Zn}(s) + \text{Cu}^{2+}(aq)
ightarrow \text{Zn}^{2+}(aq) + \text{Cu}(s) \), Zn goes from 0 (in solid) to +2 (in \( \text{Zn}^{2+} \)), so it's oxidized. Cu goes from +2 (in \( \text{Cu}^{2+} \)) to 0 (in solid Cu), so it's reduced. This is a redox reaction.

Step2: Analyze Reaction 2

In \( 2\text{Na}(s) + \text{Cl}_2(aq)
ightarrow 2\text{NaCl}(s) \), Na goes from 0 (solid) to +1 (in \( \text{NaCl} \)), oxidized. Cl goes from 0 (in \( \text{Cl}_2 \)) to -1 (in \( \text{NaCl} \)), reduced. This is a redox reaction.

Step3: Analyze Reaction 3

In \( 2\text{Mg}(s) + \text{O}_2(g)
ightarrow 2\text{MgO} \), Mg goes from 0 (solid) to +2 (in \( \text{MgO} \)), oxidized. O goes from 0 (in \( \text{O}_2 \)) to -2 (in \( \text{MgO} \)), reduced. This is a redox reaction.

Answer:

d. All of 1, 2, and 3