Question

Pick out from the following complex compounds, a poor electrolytic conductor in solution
A . K2[PtCl6]
B . [Co(NH3)3(NO2)3]
C . K4[Fe(CN)6]
D . [Cu(NH3)4]SO4

Answer 1

Hint: In this question we have checked the electrolytic conduction of a complex compound in solution and checked which of the following compound is a poor conductor.
A class of compounds with a chemical structure in which the core metal atom is surrounded by non-metal atoms or a group of atoms is known as a complex compound (or ligands). Chemical bonds such as covalent, ionic, and coordinate bonds are used to link the core atom and ligands. Because it has coordinate bonds in its structure, a complex compound is also known as a coordinate compound.

Complete answer:The ability of water to conduct an electrical current is measured by its conductivity. Conductivity rises with salinity because dissolved salts and other inorganic compounds carry electrical currents.
Based on conductivity levels, the substances can be divided into electrolytes and non-electrolytes. As Werner discovered when developing his hypothesis for coordination compounds, conductive data can be quite helpful in determining the structure of a chemical. In order to explain these observations, he established primary and secondary valence. Coordination compounds are a general term for metal complexes in which a metal atom or metal ion is linked to ligands. A coordination compound consists of ligands, and the core metal atom or ion.

The number of ions generated per mole when a complex compound is dissolved in an aqueous solution determines the electrical conductivity of the solution.

K₂[PtCl₆] will dissociate to give 3 ions. [Co(NH₃)₃(NO₂)₃] will not dissociate and not give any ions in the solution. K₄[Fe(CN)₆] will dissociate in water and give 5 ions. [Cu(NH₃)₄]SO₄ will dissociate to give two ions.
Thus, [Co(NH₃)₃(NO₂)₃] would have the least number of ions on ionisation and hence is the poor electrolytic conductor in solution.

The correct answer is B.

Note: Triammine trinitro-N-cobalt(III) is the proper name according to IUPAC of [Co(NH3)3(NO2)3]. The oxidation state of Co is +3. Cobalt has a coordination number of 6 in this compound. There are two geometric isomers of it: the trans or mer or meridional isomer and the cis or fac or facial isomer. It may demonstrate linkage isomerism. Due to its plane of symmetry, this molecule is optically inactive.