Answer
The formula for the coordination isomers of \[\left[ Fe{{\left( {{H}_{2}}O \right)}_{6}} \right]C{{l}_{2}}\]are
\[\left[ Fe{{\left( {{H}_{2}}O \right)}_{5}}Cl \right]\ \ Cl.{{H}_{2}}O\] and \[\left[ Fe{{\left( {{H}_{2}}O \right)}_{4}}C{{l}_{2}} \right].2{{H}_{2}}O\]
\[\left[ Fe{{\left( {{H}_{2}}O \right)}_{5}}Cl \right]\ \ Cl.{{H}_{2}}O\]= Pentaaquachloroiron (II) chloride monohydrate
\[\left[ Fe{{\left( {{H}_{2}}O \right)}_{4}}C{{l}_{2}} \right].2{{H}_{2}}O\]= Tetraaquadichloroiron (II) dihydrate
Work Step by Step
The compound \[\left[ Fe{{\left( {{H}_{2}}O \right)}_{6}} \right]C{{l}_{2}}\]have two different coordination isomers: \[\left[ Fe{{\left( {{H}_{2}}O \right)}_{5}}Cl \right]\ \ Cl.{{H}_{2}}O\]and \[\left[ Fe{{\left( {{H}_{2}}O \right)}_{4}}C{{l}_{2}} \right].2{{H}_{2}}O\]. In \[\left[ Fe{{\left( {{H}_{2}}O \right)}_{5}}Cl \right]\ \ Cl.{{H}_{2}}O\], one chloride ion coordinates with the metal and chloride ion as well water molecule are the counter ions. The name of this coordination isomer is Pentaaquachloroiron (II) chloride monohydrate. While in \[\left[ Fe{{\left( {{H}_{2}}O \right)}_{4}}C{{l}_{2}} \right].2{{H}_{2}}O\], two chloride ions are coordinates with the metal and two water molecules are the counter ions. The name of this coordination isomer is Tetraaquadichloroiron (II) dihydrate.