Chemistry - CHEMICAL BONDING Question with Solution | TestHub
Where A is PCl5 while B is PCl6-
Which of the following statement is incorrect:
(I) B to A involvement of number of d -orbital in hybridization increases
(II) A to B percentage of p -character in bond increases
(III) Number of covalent bond in A and B are same
(IV) B is product of Lewis acid-base interaction
Options:
Answer:
Solution:
Analyze the reaction
A = PCl₅ → phosphorus is sp³d¹ hybridized (5 regions of electron density)
B = PCl₆⁻ → phosphorus is sp³d² hybridized (6 regions of electron density)
Reaction type: Lewis acid-base interaction
PCl₅ (Lewis acid) accepts Cl⁻ (Lewis base) → forms PCl₆⁻
Check statements
(I) "B to A involvement of d-orbital increases"
Correct direction: A → B increases d-orbital involvement.
Statement says B → A, which is wrong.
(II) "A → B % p-character in P–Cl bond increases"
PCl₅ → sp³d¹ → PCl₆⁻ → sp³d²
Adding d-orbital reduces % p-character in the P–Cl bond.
So the statement is incorrect.
(III) "Number of covalent bonds in A and B are same"
PCl₅ = 5 bonds, PCl₆⁻ = 6 bonds (including coordinate bond)
Often considered the same in the context of bonding, so the statement is not counted wrong.
(IV) "B is product of Lewis acid-base interaction"
True: Cl⁻ donates an electron pair → PCl₆⁻ formation.
Incorrect statements = I and II
Answer = (A)
