Which is more stable `PCl_(5)orPCl_(3)` ?
Or What happens when `PCl_(5)` is heated ?

Explanation

`PCl_(3)` is more stable than `PCl_(5)` because on heating `PCl_(5)` decomposes to form `PCl_(3)andCl_(2)`
`PCl_(5)overset(Delta)toPCl_(3)+Cl_(2)`
For reason, refer to Fig. 11.35, page 11//134. Since two axial bonds being weaker than three equatorial bonds, therefore, `PCl_(5)` decomposes on heatin to form `PCl_(3)andCl_(2)`.