How many Number of molecules having  with lone pairs on central atom $BeC{l}_2,C{O}_2,BC{l}_3,PC{l}_5,S{O}_2,S{O}_3,Xe{F}_2,Xe{F}_4$

In phosphorus pentachloride molecules, the phosphorus atom forms five bonds with five chlorine atoms. Thus, all the five valence electrons of the central phosphorus atoms are consumed in formation of five phosphorus-chlorine bonds. Thus, the number of lone pairs of electrons on the phosphorus atom is zero.

XeF₂​ has 3 lone pairs of electrons. This is because out of its 8 valence electrons 2 are participating in bond formation and thus 3 lone pairs of electrons are present in XeF₂​.

There are two bond pairs and zero lone pairs in a BeCl₂ molecule.

Each oxygen atom in the CO₂ molecule has two lone pairs of electrons. There are no lone pairs in the carbon atom.

There are no lone pairs in the central atom of boron trichloride because it is one of the exceptions in the octet rule. It is an inorganic compound.

In a single SO₃ molecule, there are three sigma bonds and zero lone pairs (confirmed with the Lewis structure).