Ethanol to but-l-yne.

I'm sorry, but you didn't provide a specific question. However, if you're asking about the process of converting ethanol to but-1-yne, here are the steps:

1. Dehydration of Ethanol to produce Ethene: Ethanol can be dehydrated to produce ethene by heating it with an excess of concentrated sulfuric acid at about 170°C.

   CH3CH2OH (ethanol) → CH2=CH2 (ethene) + H2O

2. Bromination of Ethene to produce 1,2-Dibromoethane: Ethene reacts with bromine in an addition reaction to form 1,2-dibromoethane.

   CH2=CH2 (ethene) + Br2 → CH2Br-CH2Br (1,2-dibromoethane)

3. Dehydrobromination of 1,2-Dibromoethane to produce But-1-yne: 1,2-Dibromoethane can be converted to but-1-yne through two successive dehydrobromination reactions. The first dehydrobromination will give ethyne, and the second will give but-1-yne.

   CH2Br-CH2Br (1,2-dibromoethane) → CH≡CH (ethyne) + 2HBr CH≡CH (ethyne) → CH≡C-CH2-CH3 (but-1-yne)

Please note that this is a simplified version of the reactions and actual industrial processes may involve different conditions and additional steps.