Question

The stability of +4 oxidation state will be maximum in:

• A. C
• B. Ge
• C. Sn
• D. Pb

Answer 1

The correct option is A

C

Can you predict the trend of oxidization state?
The Stability of +4 oxidation state decreases down the group.
This is because of inert pair effect.
It is the reluctance of $n{s}^2$ electrons to unpair and participate in chemical bond formation. It arises due to the presence of lesser shielding fully filled d- and or f-electrons between the valence shell electrons and the noble gas core (shielding effects: $s>p>d>f$).
Down the group ($\downarrow$), the number of electrons in d- and /or f-orbitals increases and, hence, inert pair effect increases from Ge to Pb. Consequently, the stability of group oxidation state (+4) decreases in the order: $Ge>Sn>Pb$ and that of lower oxidation state (+2) increases in the order : $Ge<Sn<Pb$.

Therefore the stability of +4 oxidation state will be maximum in C.