What happens when `PCl_(5)` is heated ?

Explanation

Upon heating. `PCl_(5)` dissociates to give molecules of `PCl_(3) " and " Cl_(2)`. Actually, the two P-Cl (a) bonds with more bond length break away from the molecule leaving three P-Cl (e ) bonds attached to the central P atom since these are more firmly linked.
`PCl_(5) overset("heat")to PCl_(3)+Cl_(2)`