In one step ethyne can be obtained from

Options

A. ethanol
B. ethanal
C. chloroform
D. ethyl bromide

Answer

To obtain ethyne in one step, we can use chloroform as the starting material. Here’s a step-by-step solution:

### Step-by-Step Solution:

1. **Identify the Reactant**: We will use chloroform (CHCl₃) as our starting material.

2. **Reaction Setup**: We will react chloroform with silver powder (Ag). The reaction involves the elimination of chlorine atoms from chloroform.

3. **Reaction Mechanism**: The reaction can be represented as follows:
\[ 2 \text{CHCl}_3 + 6 \text{Ag} \rightarrow \text{C}_2\text{H}_2 + 6 \text{AgCl} \]
In this reaction, two molecules of chloroform react with six atoms of silver to produce ethyne (C₂H₂) and silver chloride (AgCl).

4. **Formation of Ethyne**: The elimination of chlorine atoms occurs, leading to the formation of the triple bond in ethyne.

5. **Precipitate Formation**: As a byproduct, silver chloride (AgCl) precipitates out of the solution.

### Conclusion:
Thus, ethyne can be obtained in one step from chloroform using silver powder.