Indicate the type of isomerism exhibited by the following complexes and draw the structures for these isomers:
(i) `K[Cr(H_(2)O)_(2)(C_(2)O_(4))_(2)`
(ii) `[Co(en)_(3)]Cl_(3)`
(iii) `[Co(NH_(3))_(5)(NO_(2))](NO_(3))_(2)`
(iv) `[Pt(NH_(3))(H_(2)O)Cl_(2)]`

Explanation

To solve the question, we will analyze each complex one by one, identify the type of isomerism exhibited, and then draw the structures for these isomers.

### (i) \( K[Cr(H_2O)_2(C_2O_4)_2] \)

**Step 1: Identify the type of isomerism.**
This complex is of the type \( MA_2B_2 \) (where \( M \) is the metal, \( A \) are the water ligands, and \( B \) are the oxalate ligands). Such complexes exhibit geometrical isomerism.

**Step 2: Draw the structures for the isomers.**
...