Question

The number of precipitable halide ions in the sample \[\left[ Pt\left( N{{H}_{3}} \right)C{{l}_{2}}Br \right]Cl\] will be:
A. 2
B. 3
C. 4
D. 1

Answer 1

Hint: Because the ions present in the coordination sphere do not dissociate and instead stay together in an aqueous solution, coordination compounds do not entirely break down into all of their ions. Only the substances that are joined to the complex produce ions.

Complete answer:We have been asked to find the number of precipitable ions in the given complex. Precipitation will occur only to the halogens which can be ionised from the given sample. Coordination complexes comprise of a central metal atom, a ligand, and some attacking groups which are ionizable when put in the aqueous solution. Salts can be divided into two categories, simple salt, and mixed salt, based on how many different types of ions they contain. Simple salts only include one kind of each cation and anion. For instance, KCl and NaCl. More than one type of cation or anion can be found in mixed salt. Additionally, there are two forms of mixed salts: coordination complex and double salt. Water entirely dissociates into its ion components after mixing with double salts. Water does not entirely separate coordination compounds into their cationic and anionic parts. If we look at the given complex, that is \[\left[ Pt\left( N{{H}_{3}} \right)C{{l}_{2}}Br \right]Cl\], it’s dissociation in the solution can be seen as:

\[\left[ Pt\left( N{{H}_{3}} \right)C{{l}_{2}}Br \right]Cl\to {{\left[ Pt\left( N{{H}_{3}} \right)C{{l}_{2}}Br \right]}^{+}}+C{{l}^{-}}\], here we can see that we have one free chloride ion and that’s the only halogen ion that will participate in the reaction and lead to precipitation. Therefore, there is only 1 halide ion that is precipitable.

Hence, the correct option is D. 1

Note: When naming a coordination complex, the cation is written first, followed by the anion. The center metal atom is named with its oxidation number in roman numerals after the ligands are named in alphabetical order during the naming of the coordination sphere.