Question

In solid state, $PC{l}_5$ exists as an ionic solid ${\left[PC{l}_X\right]}^{+}{\left[PC{l}_Y\right]}^{-}.$ What is the value of $Y?$

Answer 1

Answer: 6

In solid state, $PC{l}_5$ exists as ${\left[PC{l}_4\right]}^{+}{\left[PC{l}_6\right]}^{-}.$
The geometry of the $PC{l}_5$ is the trigonal bipyramidal. The geometry of the ${\left[PC{l}_4\right]}^{+}$ ion is tetrahedral. The geometry of the ${\left[PC{l}_6\right]}^{-}$ ion is the octahedral.
Hence, $Y$ is $6.$