Question

Which of the following is non-ionisable?
(A) \[[Co{{(N{{H}_{3}})}_{3}}C{{l}_{3}}]\]
(B) \[[Co{{(N{{H}_{3}})}_{4}}C{{l}_{2}}]Cl\]
(C) \[[Co{{(N{{H}_{3}})}_{5}}Cl]C{{l}_{2}}\]
(D) \[[Co{{(N{{H}_{3}})}_{6}}]C{{l}_{2}}\]

Answer 1

Hint: Ionisable compounds are those compounds in which counter ions are present and in non-ionisable compound counter ions are not present. From the options, choose the ones which don't have a counter ion.

Complete step by step solution:
Ionisable and non-ionisable compounds are generally discussed in the presence of counter ions. In case of coordination, compound counter ions are the anions or cations not involved in the coordination. In a general way, counter-ions can affect the crystallization of coordination polymer products, leading to different coordination structures.
(A) \[[Co{{(N{{H}_{3}})}_{3}}C{{l}_{3}}]\]: In this case, there are no anions or cations are present which can take participate in the formation of complex i.e. it does not have any counterion.
(B) \[[Co{{(N{{H}_{3}})}_{4}}C{{l}_{2}}]Cl\]: In this case chloride ion outside the coordination, the sphere can act as counter ion so it is ionisable compound.
(C) \[[Co{{(N{{H}_{3}})}_{5}}Cl]C{{l}_{2}}\]: It consists of two chloride ion i.e. two counter ions so it is ionisable in nature.
(D) \[[Co{{(N{{H}_{3}})}_{6}}]C{{l}_{2}}\]: There are also two chloride atoms are present which can be considered as counter ions so it is also ionisable in nature.

Thus, (A) is the only compound which has no counter ions and is non-ionisable in nature.

Note: The coordination sphere is the cation or anion which consists of a system of a central atom surrounded by neutral or negatively charged ligands which are stable enough to be considered as a single cation or anion and counterion is the simple cations or anions that may or may not participate in the coordination.