Which of the following tests could be performed to distinguish between 1-butyne and 2-butyne. ?

Options

A. `Ag^(+)//NH_(3)`
B. `Br_(2)//C Cl_(4)`
C. `H_(2)//Pt`
D. `Hg^(+2)//H_(2)SO_(4)`

Answer

To distinguish between 1-butyne and 2-butyne, we can perform a chemical test using the Tollen's reagent (Ag(NH3)2+). Here’s a step-by-step solution:

### Step 1: Understand the Structures
1-butyne (C4H6) is a terminal alkyne, meaning it has a triple bond at the end of the carbon chain. Its structure is CH3-CH2-C≡C-H. This terminal alkyne has one acidic hydrogen atom attached to the carbon with the triple bond.

2-butyne (C4H6), on the other hand, is an internal alkyne with the structure CH3-C≡C-CH3. It does not have an acidic hydrogen atom because the triple bond is between two carbon atoms that are both bonded to other carbon atoms.

### Step 2: Perform the Test
We can use Tollen's reagent (Ag(NH3)2+) to test for the presence of acidic hydrogen:
- When 1-butyne is treated with Tollen's reagent, the acidic hydrogen will react with the silver ion (Ag+) to form a complex, resulting in the formation of a silver acetylide (CH3-CH2-C≡C-Ag) and releasing ammonia and water as byproducts.

- In contrast, when 2-butyne is treated with Tollen's reagent, there is no acidic hydrogen available for reaction, so no reaction will occur.

### Step 3: Analyze the Results
- If a reaction occurs (indicated by the formation of a silver complex), we conclude that the compound is 1-butyne.
- If no reaction occurs, we conclude that the compound is 2-butyne.

### Conclusion
The test using Tollen's reagent can effectively distinguish between 1-butyne and 2-butyne. The correct answer is that Tollen's reagent can be used to differentiate between the two.

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