Total number of meso forms possible for 1,2,3,4 -Tetrachlorocyclobutane.

Answer

To determine the total number of meso forms possible for 1,2,3,4-tetrachlorocyclobutane, we will follow these steps:

### Step 1: Understand the Structure
1. **Identify the structure of 1,2,3,4-tetrachlorocyclobutane**: This compound consists of a cyclobutane ring with chlorine atoms attached to the 1st, 2nd, 3rd, and 4th carbon atoms.

### Step 2: Identify Chiral Centers
2. **Determine if there are chiral carbon atoms**: A chiral carbon atom is one that has four different groups attached to it. In our case, we need to analyze each carbon in the cyclobutane ring.
- Each carbon in the cyclobutane ring is attached to two hydrogen atoms and one chlorine atom. Since there are two identical hydrogen atoms on each carbon, none of the carbons have four different groups attached.

### Step 3: Analyze for Meso Forms
3. **Check for the presence of a plane of symmetry (POS)**: A meso compound must have a plane of symmetry. Since there are no chiral centers in 1,2,3,4-tetrachlorocyclobutane, it cannot have a plane of symmetry that would lead to meso forms.

### Step 4: Conclusion
4. **Count the meso forms**: Since there are no chiral carbon atoms in the structure, there are no meso forms possible for 1,2,3,4-tetrachlorocyclobutane.

### Final Answer
The total number of meso forms possible for 1,2,3,4-tetrachlorocyclobutane is **zero**.

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