How many geometrical isomers are possible in the following corrdination entities?
(i). `[Cr(C_2O_4)_3]^(3-)`
(ii). `[Co(NH_3)_3Cl_3]`

Explanation

To determine the number of geometrical isomers for the given coordination entities, we will analyze each compound step by step.

### Step 1: Analyze the first coordination compound `[Cr(C2O4)3]^(3-)`

1. **Identify the Ligands and Coordination Number:**
- The coordination compound contains chromium (Cr) and oxalate ions (C2O4).
- The oxalate ion is a bidentate ligand, meaning it can form two bonds with the central metal ion.
- Since there are three oxalate ligands, the coordination number of chromium in this complex is 6.
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