Question

Give reasons When Cl₂ reacts with the excess of F₂, ClF₃ is formed and not FCl₃.

Answer 1

Fluorine does not possess d orbitals, so it cannot expand its octet to bond with three chlorine atoms and form FCl₃. Chlorine, on the other hand, has empty d orbitals and thus, it can expand its octet to bond with three fluorine atoms and form ClF₃.