Q57 P - Chemistry: Molecular Nature Of Matter And Change

Question

What are the charge and coordination number of the central metal ion(s) in each compound of Problem 23_55?

Step-by-Step Solution

Answer

$\left[Ni{\left({\mathrm{H}}_2\mathrm{O}\right)}_6\right]C{l}_2$ - Coordination number: 6; charge: +2

$\left[\mathrm{Cr}{\left(\mathrm{en}\right)}_3\right]{\left({\mathrm{ClO}}_4\right)}_3$ - Coordination number: 6 charge: +3

width="94" height="24" style="max-width: none; vertical-align: -9px;" $K_4\left[\mathrm{Mn}{\left(\mathrm{CN}\right)}_6\right]$ Coordination number: 6 charge: +2

Step 1: Definition of Coordination Compound

A coordination complex consists of a central atom or ion, which is usually metallic and is called the coordination centre, and a surrounding array of bound molecules or ions, that are in turn known as ligands or complexing agents.

Step 2: Solve the given statements

The coordination number is the number of ligands directly attached to central metal ion in a coordination compound. These ligands can be ions, atoms or molecules. The most common coordination number is 0, but it is also not rare to see 2 and 4 as coordination numbers.

$\left[Ni{\left({\mathrm{H}}_2\mathrm{O}\right)}_6\right]C{l}_2$ - There are six ligands (H₂O) bonded with central metal ion ( (Ni) so the coordination number of central metal ion is 6 . H₂O is neutral ligand and Cl is counter ion with -l charge, so the charge of the central metal ion will be +2

$\left[\mathrm{Cr}{\left(\mathrm{en}\right)}_3\right]{\left({\mathrm{ClO}}_4\right)}_3$ - There are three bidentate ligands (en) bonded with central metal ion (Cr), so the coordination number of central metal ion is 6. en is neutral ligand and CIO₄ is a counter ion with -1 charge, so the charge of the central metal ion will be +3

$K_4\left[\mathrm{Mn}{\left(\mathrm{CN}\right)}_6\right]$ - There are six ligands (CN) around central metal ion (Mn), so the coordination number of central metal ion will be 6 . CN has - 1 charge and is a counter ion with charge, so the charge of the central metal ion will be +2