Stereoisomerism occurs when the bond connectivity is same but the spatial arrangement of more than one type is possible. Stereoisomerism finds vast use in orgaic chemistry, mainly biochemistry as all the biomolecules, are generally stereospecific in their actions. Stereoisomerism in limited not only to organic compounds but also to inorganic compounds, mainly in co-ordination complexes. Stereoisomers include cis and trans isomers, chiral isomers, compound wilth different conformation of chelate rings and other isomers that differ only in the geometry of attachement of the metal ion.
Select the correct option for tertraamminedichlorocobalt (III) ion, the trans isomer

Options

A. does not have any symmetry
B. has plane of symmetry
C. trans form is meso form
D. trans form exists as a pair of ennantiomer

Explanation

To solve the question regarding the trans isomer of tetraamminedichlorocobalt(III) ion, we will follow these steps:

### Step-by-Step Solution:

1. **Understanding the Coordination Complex**:
- The complex in question is tetraamminedichlorocobalt(III), which has the formula [Co(NH3)4Cl2]⁺.
- It consists of one cobalt ion (Co³⁺) surrounded by four ammonia (NH3) ligands and two chloride (Cl⁻) ligands.

2. **Identifying Isomerism**:
- This complex can exhibit stereoisomerism due to the different spatial arrangements of the ligands around the central cobalt ion.
- The two types of isomers we can have are cis and trans isomers.

3. **Drawing the Structures**:
- **Trans Isomer**: In the trans configuration, the two chloride ions are positioned opposite each other, while the four ammonia ligands occupy the remaining positions.
- Visualize the cobalt ion at the center, with two chlorides on opposite sides and the four ammonia ligands in a plane around it.
- **Cis Isomer**: In the cis configuration, the two chloride ions are adjacent to each other, with the ammonia ligands filling the remaining positions.

4. **Analyzing Symmetry**:
- The trans isomer will have both an axis of symmetry and a plane of symmetry due to the opposite placement of the chloride ions.
- The cis isomer will not have this symmetry because the chlorides are adjacent.

5. **Selecting the Correct Option**:
- Based on the symmetry analysis, the trans isomer of tetraamminedichlorocobalt(III) will have a plane of symmetry.
- Therefore, the correct option for the trans isomer is the one that indicates it has a plane of symmetry.

### Final Answer:
The correct option for the trans isomer of tetraamminedichlorocobalt(III) ion is the one that states it has a plane of symmetry.

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