PCl₅ exists as [PCl₆]^– [PCl₄]⁺ but PBr₅ exists as [PBr₄] + [Br]^–. Explain.

Both PCl₅ and PBr₅ have trigonal bipyramidal geometry. This is not a regular structure and is not very stable. Therefore, PCl₅ splits up into more stable octahedral and tetrahedral structures. Which are stable than trigonal bipyramidal.

{PCl}_{5} ⇌ {[{PCl}_{6}]}^{-} {[{PCl}_{4}]}^{+}

On the other hand, PBr₅ splits up into stable tetrahedral structure as [PBr₄]⁺ [Br]^{–
${PCl}_{5} ⇌ {[{PBr}_{4}]}^{+} {[Br]}^{-}$}This splitting is different from PCl₅ because Br atoms are large and six atoms of Br cannot be easily accommodated around smaller P atom.

1196 Views

The p-Block Elements

Hope you found this question and answer to be good. Find many more questions on The p-Block Elements with answers for your assignments and practice.

Chemistry I

Browse through more topics from Chemistry I for questions and snapshot.

PCl5 exists as [PCl6]– [PCl4]+ but PBr5 exists as [PBr4] + [Br]–. Explain.

The p-Block Elements

Chemistry I

PCl₅ exists as [PCl₆]^– [PCl₄]⁺ but PBr₅ exists as [PBr₄] + [Br]^–. Explain.