NEETChemistryClassification of Elements and Periodicity in Properties
Based on the stability of oxidation states dictated by the inert pair effect, which of the following redox reactions is thermodynamically most feasible?
Options
- ASn ²⁺ + Pb ⁴⁺ Sn ⁴⁺ + Pb ²⁺
- BPb ²⁺ + Sn ⁴⁺ Pb ⁴⁺ + Sn ²⁺
- CTl ⁺ + In ³⁺ Tl ³⁺ + In ⁺
- DPb ²⁺ + Ge ⁴⁺ Pb ⁴⁺ + Ge ²⁺
Correct answer
A. Sn ²⁺ + Pb ⁴⁺ Sn ⁴⁺ + Pb ²⁺
Step-by-step solution
Due to the inert pair effect, the stability of the lower oxidation state increases down the group for p-block elements. In Group 14, the +4 oxidation state is more stable for lighter elements like Sn, while the +2 oxidation state is more stable for the heaviest element Pb. Therefore, Sn ²⁺ tends to oxidize to Sn ⁴⁺ (acting as a reducing agent), and Pb ⁴⁺ tends to reduce to Pb ²⁺ (acting as an oxidizing agent). Thus, the reaction Sn ²⁺ + Pb ⁴⁺ Sn ⁴⁺ + Pb ²⁺ is highly feasible as both elements proceed towards their m