Question

why KHF2 is known but KHCl2 is not known?

Answer 1

KHF₂ is an ionic compound with K⁺ and HF₂. But when there is HCl₂ ion, the size of anion become so large that K⁺ ion becomes smaller then the size of its smallest void. 


(Hope this answer is useful)

Answer 2

The size of anion becomes so large and denotes K+ ion becomes smaller.

F is much more electronegative than Cl hence has much stronger hydrogen bonding, which stabilizes the structure with anion F-.

Note- H2F2 exists as dimeric molecule due to H–bonding and thus shows dibasic nature. Hence it gives two series of salts KHF2 and KF.