Q77P - Chemistry: Molecular Nature Of Matter And Change

Question

Chromium(III), like cobalt(III), has a coordination number of 6 in many of its complex ions. Compounds are known that have the traditional formula CrCl3_nNH3, where n = 3 to 6. Which of the compounds has an electrical conductivity in an aqueous solution similar to that of an equimolar NaCl solution?

Step-by-Step Solution

Answer

The compound will be CrCl₃ .3NH₃ where one of the isomers of the compound will be $\left[{\text{CrCl}}_2{\left({\text{NH}}_3\right)}_3\right]\text{Cl}$, which produces two ions: ${\left[{\text{CrCl}}_2{\left({\text{NH}}_3\right)}_3\right]}^{+}$ and Cl^-, with conductivity similar to an equimolar solution of NaCl.

Step 1: Definition of Coordination Compound

A coordination complex is made up of a core atom or ion, known as the coordination center, which is typically metallic, and an array of attached molecules or ions that are known as ligands or complexing agents.

 

Step 2: The electrical conductivity in aqueous solution

Of the compounds in the traditional CrCl_3. NH₃ with n=3 to 6, the compound with electrical conductivity equivalent to an equimolar solution is when n = 3, thus the compound will be where one of the isomers of the compound will be $\left[{\text{CrCl}}_2{\left({\text{NH}}_3\right)}_3\right]{\text{Cl}}^2$ which produces two ions: ${\left.{\text{CrCl}}_2{\left({\text{NH}}_3\right)}_3\right]}^{+}$and Cl^-, with conductivity similar to an equimolar solution of NaCl.