Doubtify – JEE Ki Taiyaari, Simple Bhasha Mein

  ❓ Question Why is Al³⁺ stable , Tl⁺ highly stable , and Tl³⁺ a strong oxidising agent? Let’s break the entire concept in one crisp explanation. ✍️ Short Explanation The inert pair effect refers to the reluctance of the ns² electrons (the "inert pair") to participate in bonding for heavy p-block elements . This means as we go down a group, especially in groups 13–16 , the lower oxidation state becomes more stable , and the higher oxidation state becomes less stable . Let's apply this to Group 13: Al → Ga → In → Tl . 🔹 1. Why Al³⁺ is Stable Aluminium is in the 3rd period . Relativistic effects are very small. The 3s² electrons are not inert — they easily participate in bonding. So Al prefers oxidation state +3 (Al³⁺). 👉 Al³⁺ is very stable, does not get reduced easily. 🔹 2. Why Tl⁺ is More Stable than Tl³⁺ Thallium (Tl) is in the 6th period . The 6s² electrons are held tightly due to relativistic contraction. They behave like ...

❓ 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 Solution We evaluate each statement using electronic structure, standard electrode potentials and chemical trends (inert-pair effect, stability of Al³⁺). 🔹 (A) Tl³⁺ is a powerful oxidising agent — True Tl in +3 state has electronic configuration [Xe]4f¹⁴5d¹⁰ (6s⁰6p¹ for neutral Tl → Tl³⁺ has lost the 6p and 6s electrons partially). Due to the inert-pair effect , the 6s electrons are reluctant to participate in bonding; Tl³⁺ is stabilized poorly and tends to be reduced to Tl⁺. Thus Tl³⁺ accepts electrons readily → it is a strong oxidizing agent (gets reduced to the more stable Tl⁺). Example: Tl³⁺ is often reduced in aqueous solution; TlCl₃ disproportionates, etc. 🔹 (B) Al³⁺ d...