The factor responsible for weak acidic nature of B-F bonds in BF3 is

A
large electronegativity of fluorine
B
three centred two electron bonds in BF₃.
C
$pπ - dπ$ back bonding.
D
$pπ - pπ$ back bonding.

Solution:

BF₃ is electron-deficient because B only has six valence electrons. B has one empty 2p orbital, while each F has three lone pairs of electrons. B and F have similar sizes, as a result, B and F orbitals show effective overlapping. Therefore, F can share one of its lone pairs with the unoccupied orbital of B. This results in the formation of $pπ - pπ$ back bonding. This provides additional strength to the B-F bond and makes the B-F bond less acidic.

The factor responsible for weak acidic nature of B-F bonds in BF₃ is

Solution:

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