Name the reagent X' in the reaction :
`1,2-"Dibromoethane" overset(X)to "Acetylene"`

Answer

To determine the reagent X in the reaction of 1,2-Dibromoethane to form Acetylene, we can follow these steps:

### Step 1: Understand the Reactants
1,2-Dibromoethane (C2H4Br2) contains two bromine atoms attached to the two carbon atoms of ethane. The structure can be represented as:
```
Br Br
| |
H - C - C - H
```

### Step 2: Identify the Product
The product is Acetylene (C2H2), which has a triple bond between the two carbon atoms:
```
H - C ≡ C - H
```

### Step 3: Determine the Reaction Type
The transformation from 1,2-Dibromoethane to Acetylene involves the removal of two bromine atoms and two hydrogen atoms. This indicates that an elimination reaction is taking place.

### Step 4: Identify the Reagent for Elimination
In elimination reactions, particularly when converting a dihaloalkane to an alkyne, a strong base is typically used. The reagent that facilitates this reaction is alcoholic KOH (Potassium Hydroxide in alcohol).

### Step 5: Mechanism of the Reaction
1. The alcoholic KOH acts as a base and abstracts a proton (H) from one of the carbon atoms.
2. This leads to the formation of a double bond between the two carbon atoms and the elimination of one bromine atom.
3. The process is repeated, where the base abstracts another proton, resulting in the formation of a triple bond and the elimination of the second bromine atom.

### Conclusion
The reagent X in the reaction of 1,2-Dibromoethane to Acetylene is **alcoholic KOH**.

---