Chemistry - CHEMICAL BONDING Question with Solution | TestHub

In (B): $p\pi -d\pi$ back-bonding from oxygen to the vacant $d$-orbitals of silicon decreases electron density on oxygen, making the O–H bond more polar and thus more acidic.

In (C): The nitrogen lone pair in (SiH₃)₃N is delocalized into silicon's vacant $d$-orbitals via back-bonding, making the lone pair less available for donation and reducing its Lewis basicity.

In contrast, (A) is primarily governed by atomic radii differences, and (D) is due to the poor overlap of larger $3p$ orbitals.
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