Inert Pair Effect ⚡ Oxidising vs Reducing

 

❓ Concept Question

In Group 14 elements, how do we determine whether ions like $A^{2+}$ or $B^{4+}$ behave as oxidising or reducing agents?

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🖼 Concept Image

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✍️ Short Concept

Redox nature in p-block depends on:

👉 Ionisation enthalpy
👉 Stability of oxidation states
👉 Inert pair effect

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🔷 Step 1 — Lowest Ionisation Enthalpy 💯

Lowest IE means:

👉 Electron dena easy

So element shows:

• Metallic character
• Electropositive nature

👉 Common in lower group elements (Sn, Pb)

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🔷 Step 2 — Oxidation State Stability

Group 14 shows:

$$+2 \quad \text{and} \quad +4$$

Trend:

Down the group:

👉 $+2$ becomes more stable
👉 $+4$ becomes less stable

Reason:

$$\textbf{Inert Pair Effect}$$

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🔷 Step 3 — Nature of $A^{2+}$

If +2 is stable:

$$A^{2+} \rightarrow \text{stable ion}$$

Such ions tend to lose electrons further:

👉 Act as reducing agents

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🔷 Step 4 — Nature of $B^{4+}$

If +4 is unstable:

$$B^{4+} \rightarrow \text{easily reduced to } +2$$

So it accepts electrons:

👉 Acts as oxidising agent

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🔷 Step 5 — One-Line JEE Logic

$$\boxed{ \text{Stable lower state} \rightarrow \text{reducing} }$$
$$\boxed{ \text{Unstable higher state} \rightarrow \text{oxidising} }$$

👉 Group 14 + inert pair effect = instant answer

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✅ Final Takeaway

• $A^{2+}$ → reducing agent
• $B^{4+}$ → oxidising agent

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⭐ Golden JEE Insight

Down the group:

👉 Inert pair effect increases

So:

$$+2 \text{ preferred over } +4$$

Especially for Sn and Pb.