MolSynapsequestion bank

MolSynapse / Question bank / p-Block Elements: Groups 15 and 16 / Phosphorus allotropes, phosphine, halides and oxyacids of phosphorus

JEE Main levelSingle correct optionDifficulty 2 of 3pn135

In the solid state, phosphorus pentachloride exists as

Asquare pyramidal molecules
Bdiscrete trigonal bipyramidal molecules only
C $[PCl X_{6}] X^{+} [PCl X_{4}] X^{-}$ with octahedral cation
D $[PCl X_{4}] X^{+} [PCl X_{6}] X^{-}$ with tetrahedral cation and octahedral anion

Answer: D

In the crystal, PCl5 undergoes ionic disproportionation to

[PCl X_{4}] X^{+}

(sp3, tetrahedral) and

[PCl X_{6}] X^{-}

(sp3d2, octahedral). The trigonal bipyramidal structure is that of the gas phase.

Practice p-Block Elements: Groups 15 and 16 More on Phosphorus allotropes, phosphine, halides and oxyacids of phosphorus

Previous questionNext question

More questions on Phosphorus allotropes, phosphine, halides and oxyacids of phosphorus