Indicate the types of isomerism exhibited by the follow complexes and draw the structures for these isomers :
`K[Cr(H_(2)O)_(2)(C_(2)O_(4))_(2)]`

Explanation

`K[Cr(H_(2)O)_(2)(C_(2)O_(4))_(2)]" or "K[Cr(H_(2)O)_(2)("ox")_(2)]` :
(where, ox = oxalate ion)
a) It exists as geometrical isomers : cis and trans forms. (In cis form, the same groups occupy adjacent positions while in trans form, they are present at alternate positions.)

The cis isomer can also exist as a pair of optical isomers (i.e. , d-and 1-forms) (due to absence of plane of symmetry).