Stability and Redox Nature of Al and Tl Ions

 

❓ Question

Which of the following statements are correct?

(A) Tl³⁺ is a powerful oxidising agent
(B) Al³⁺ does not get reduced easily
(C) Both Al³⁺ and Tl³⁺ are very stable in solution
(D) Tl⁺ is more stable than Tl³⁺
(E) Al³⁺ and Tl⁺ are highly stable

---

🖼️ Question Image

---

✍️ Short Explanation

This problem is based on:

👉 Inert pair effect
👉 Stability of oxidation states
👉 Oxidising nature.

Main idea:

In Group 13:

$$+3 \text{ state stability decreases down the group}$$

while:

$$+1 \text{ state stability increases}$$

because of inert pair effect.

---

🔷 Step 1 — Statement (A) 💯

$$Tl^{3+}$$

readily changes to:

$$Tl^+$$

So it easily gets reduced.

Hence it acts as a:

$$\boxed{ \text{Strong oxidising agent} }$$

✔ Statement (A) is correct.

---

🔷 Step 2 — Statement (B)

Aluminium strongly prefers:

$$+3$$

oxidation state.

Thus:

$$Al^{3+}$$

does not reduce easily.

✔ Statement (B) is correct.

---

🔷 Step 3 — Statement (C)

$$Tl^{3+}$$

is NOT stable in solution due to inert pair effect.

It prefers:

$$Tl^+$$

Hence statement (C) is false.

❌ Incorrect.

---

🔷 Step 4 — Statement (D)

Because of inert pair effect:

$$Tl^+$$

is more stable than:

$$Tl^{3+}$$

✔ Correct.

---

🔷 Step 5 — Statement (E)

Stable oxidation states are:

$$Al^{3+}$$

and

$$Tl^+$$

✔ Correct.

---

🔷 Step 6 — Final Correct Statements

Correct statements:

$$(A),\ (B),\ (D),\ (E)$$

Incorrect:

$$(C)$$

---

🔷 Step 7 — JEE Trap Alert 🚨

❌ $Tl^{3+}$ ko stable maan lena

❌ Inert pair effect ignore kar dena

Remember:

Down Group 13:

$$\boxed{ +1 \text{ oxidation state becomes more stable} }$$

especially for Tl.

---

✅ Final Answer

$$\boxed{ (A),\ (B),\ (D)\text{ and }(E)\text{ only} }$$

(Option 3)

---

📚 Related Topics

• Carius Method Bromine Percentage Calculation
• Coordination Compounds Hybridization and Magnetism
• Nernst Equation with Faraday Electrolysis Concept