The primary reason that an ionic compound with formula KCl2 does not form is:
(a) The energy required to form Cl⁻ from Cl is too high.
(b) The energy required to form K²⁺ from K is too high.
(c) The lattice energy for KCl2 is less than that of the more stable KCl.
(d) The formation of K⁺ from K releases energy while the formation of K²⁺ requires energy.
(e) K²⁺ is a much larger cation than K, so it cannot be accommodated as easily in a crystal lattice.