Question

I. Which of the following structural descriptions is/are inconsistent with the stoichion etry of the salt being described? (a) The compound CdClh adapts an hop lattice of chloride ions in which all of the octahedral holes are occupied by cadmium ions (b) The compound CdCl2 adapts a cep lattice of chloride ions in which one-halfof the octahedral holes are occupied by cadmium ions. (c) The compound Li so, adapts an hep lattice of sulfate ions in which all of the tetrahedral holes are occupied by lithium ions. (d) The compound (CH3)4NF adapts a ccp lattice of tetramethy. lammonium ions in which all of the octahedral holes are occupied by fluoride ions (e) The compound Rb2CsC6o adopts a close-packed lattice in which the Rbt ions occupy all octahedral holes and the Cs+ ions occupy all tetrahedral holes

Answer 1

Option (a)

Explanation: If CdCl₂ adapts an hcp lattuce of chloride ions, then the formula will become Cd₃Cl₆

The no. of octahedral voids (holes) per each chloride ion = 1

Therefore, there are a total of 6×1 = 6 octahedral voids.

But there are only 3 cadmium ions, as a result only half of the octahedral voids are occupied by cadmium ions. But, the given statement in option (a) is that all of the octahedral voids are occupied by Cadmium ions. Hence, option (a) is inconsistent with the stoichiometry of the salt CdCl₂.