Question

question 11
in the reaction below, which element is oxidized?
mn(s) + cui₂(aq) → mni₂(aq) + cu(s)
○ cu
○ mn
○ i
○ none. this isnt a redox reaction.
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question 12
using the activity series, predict if the following reaction will occur, and the chemical formulas of the products that will form.
zn(s) + pb(c₂h₃o₂)₂(aq) →
○ spontaneous, znc₂h₃o₂ and pb
○ spontaneous, znpb and c₂h₃o₂
○ spontaneous, zn(c₂h₃o₂)₂ and pb
○ spontaneous, zn(c₂h₃o₂)₃ and pb
○ not spontaneous (no reaction)
activity series of metals
zn(s) → zn²⁺(aq) + 2e⁻
pb(s) → pb²⁺(aq) + 2e⁻

Explanation:

Question 11

Step1: Recall Oxidation Definition

Oxidation is loss of electrons (increase in oxidation state).

Step2: Analyze Mn Oxidation State

• Mn(s): oxidation state = 0.
• In \( \text{MnI}_2 \), I is -1, so Mn: \( x + 2(-1) = 0 \Rightarrow x = +2 \).

Mn goes from 0 to +2 (loses electrons) → oxidized.

Step3: Analyze Cu Oxidation State

• In \( \text{CuI}_2 \), Cu: \( x + 2(-1) = 0 \Rightarrow x = +2 \).
• Cu(s): oxidation state = 0.

Cu goes from +2 to 0 (gains electrons) → reduced.

Step4: Analyze I Oxidation State

• In \( \text{CuI}_2 \) and \( \text{MnI}_2 \), I is -1 (no change) → not oxidized/reduced.

Step5: Check Redox Reaction

Since Mn is oxidized and Cu is reduced, it is a redox reaction.

Step1: Activity Series Principle

A metal displaces another if it is more reactive (higher in activity series).
From the activity series: \( \text{Zn}(s)
ightarrow \text{Zn}^{2+}(aq) + 2e^- \) and \( \text{Pb}(s)
ightarrow \text{Pb}^{2+}(aq) + 2e^- \).
Zn loses electrons more easily (more reactive) than Pb, so Zn displaces \( \text{Pb}^{2+} \) from \( \text{Pb(C}_2\text{H}_3\text{O}_2\text{)}_2 \).

Step2: Predict Products

The reaction is a single displacement: \( \text{Zn}(s) + \text{Pb(C}_2\text{H}_3\text{O}_2\text{)}_2(aq)
ightarrow \text{Zn(C}_2\text{H}_3\text{O}_2\text{)}_2(aq) + \text{Pb}(s) \).
Zn has a +2 charge, so it forms \( \text{Zn(C}_2\text{H}_3\text{O}_2\text{)}_2 \) (since \( \text{C}_2\text{H}_3\text{O}_2^- \) is -1, 2 ions balance +2).

Step3: Check Spontaneity

Since Zn is more reactive than Pb, the reaction is spontaneous.

Answer:

B. Mn

Question 12