The primary reason that an ionic compound with the formula KCl_2 does not form is:
a. The energy required to form Cl^- from Cl is too high.
b. The energy required to form K_2^+ from K is too high.
c. The lattice energy for KCl_2 is less than that of the more stable KCl.
d. The formation of K^+ from K releases energy, while the formation of K_2^+ requires energy.
e. K2^+ is a much larger caption than K^+, so it cannot be accommodated as easily in a crystal lattice.