Chapter 19, Problem 83AE

Interpretation Introduction

Interpretation: The enthalpy change for the given reaction, order of the entropy change and formation constant relation with $\Delta \text{S}°$ and chelate effect of penten and en needs to be determined.

  $\begin{array}{l}{\text{Ni}}^{\text{+2}}{}_{\text{(aq)}}{\text{+ 6NH}}_{\text{3(aq)}}𑨀{\text{Ni(NH}}_{\text{3}}{\text{)}}_{\text{6}}^{\text{2+}}{}_{\text{(aq)}}{\text{ K}}_{\text{f}}\text{= 3}{\text{.2×10}}^{\text{8}}\\ {\text{Ni}}^{\text{+2}}{}_{\text{(aq)}}{\text{+ 3 en}}_{\text{(aq)}}𑨀{\text{Ni(en)}}_3^{\text{2+}}{}_{\text{(aq)}}{\text{ K}}_{\text{f}}\text{= 1}{\text{.6×10}}^{\text{18}}\\ {\text{Ni}}^{\text{+2}}{}_{\text{(aq)}}{\text{+ penten }}_{\text{(aq)}}𑨀{\text{Ni(penten)}}_{}^{\text{2+}}{}_{\text{(aq)}}{\text{ K}}_{\text{f}}\text{= 2}{\text{.0×10}}^{\text{19}}\end{array}$

Concept Introduction: A coordination complex is composed of two main parts; metal atom/ ion and ligand. Ligands are the atom/ group of atom/ ion that can donate its extra pair of electrons to the electron deficient metal cation. It leads to the formation of coordinate bond between metal ion and ligand.