Statement I: Fe3+ is more stable than Fe2+
Statement II: Fe3+ ion has more number of unpaired electrons than Fe2+
Answer & explanation
Correct answer: option 2
The correct answer is option 2 — both statements are true, but Statement II is NOT the correct explanation of Statement I.
Statement I: Fe³⁺ is more stable than Fe²⁺ → True
Fe³⁺ has a half-filled 3d⁵ configuration, which gives extra stability due to symmetry and exchange energy.
Statement II: Fe³⁺ has more unpaired electrons than Fe²⁺ → True
Fe³⁺ → 3d⁵ → 5 unpaired electrons
Fe²⁺ → 3d⁶ → 4 unpaired electrons
But the stability is NOT because of “more unpaired electrons” directly. It is specifically due to the half-filled configuration (3d⁵), which is a special case of stability.
Having more unpaired electrons is just a result, not the reason.
So,Statement II is true, but it does not correctly explain the stability in Statement I.