Answer
\[\left[ Co{{\left( en \right)}_{3}} \right]\left[ Cr{{\left( ox \right)}_{3}} \right]\] and \[\left[ Cr{{\left( en \right)}_{3}} \right]\left[ Co{{\left( ox \right)}_{3}} \right]\] are coordination isomers.
\[\left[ Co{{\left( en \right)}_{3}} \right]\left[ Cr{{\left( ox \right)}_{3}} \right]\] = Tris (ethylenediamine) cobalt (III) trioxalatochromate (III)
\[\left[ Cr{{\left( en \right)}_{3}} \right]\left[ Co{{\left( ox \right)}_{3}} \right]\] = Tris (ethylenediamine) chromium (III) trioxalatocobaltate (III)
Work Step by Step
The compound \[\left[ Co{{\left( en \right)}_{3}} \right]\left[ Cr{{\left( ox \right)}_{3}} \right]\]have two different coordination isomers: \[\left[ Co{{\left( en \right)}_{3}} \right]\left[ Cr{{\left( ox \right)}_{3}} \right]\]and \[\left[ Cr{{\left( en \right)}_{3}} \right]\left[ Co{{\left( ox \right)}_{3}} \right]\]. In \[\left[ Co{{\left( en \right)}_{3}} \right]\left[ Cr{{\left( ox \right)}_{3}} \right]\], ethylenediamine coordinates with the metal cobalt and oxalate ion with the metal chromium. The name of this coordination isomer is Tris (ethylenediamine) cobalt (III) trioxalatochromate (III). While in \[\left[ Cr{{\left( en \right)}_{3}} \right]\left[ Co{{\left( ox \right)}_{3}} \right]\], ethylenediamine coordinates with the metal chromium and oxalate ion with the metal cobalt. The name of this coordination isomer is Tris (ethylenediamine) chromium (III) trioxalatocobaltate (III)
