Convert the following:(i) Ethanol to But - 2 - yne(ii) But - 1 - ene to n-butyl iodide(iii) Ethanol to propane nitrile

(i) Converting Ethanol to But-2-yne:
To convert ethanol to but-2-yne, you can follow these steps:

Dehydrate ethanol to form ethene (also known as ethylene). You can use a strong acid like sulfuric acid (H2SO4) as a catalyst to facilitate this reaction:

CH3CH2OH (Ethanol) → CH2=CH2 (Ethene)

Once you have ethene, you can perform a reaction known as a "hydrohalogenation" or "halogenation" to add a bromine atom to one of the carbon atoms in the ethene molecule. In this case, you want to add a bromine atom to the second carbon atom to form 1-bromoethene:

CH2=CH2 (Ethene) + HBr → CH2=CHBr (1-Bromoethene)

Finally, convert 1-bromoethene to but-2-yne through a substitution reaction using sodium amide (NaNH2) or another appropriate reagent:

CH2=CHBr (1-Bromoethene) + NaNH2 → CH≡C-CH3 (But-2-yne)

(ii) Converting But-1-ene to n-Butyl Iodide:
To convert 1-butene to n-butyl iodide, you can follow these steps:

Start with 1-butene:

CH2=CH-CH2-CH3 (1-Butene)

Perform a halogenation reaction with iodine (I2) and a suitable solvent such as chloroform (CHCl3) to replace one of the hydrogen atoms with iodine:

CH2=CH-CH2-CH3 (1-Butene) + I2 → CH2=CH-CH2-CH2I (n-Butyl Iodide)

(iii) Converting Ethanol to Propane Nitrile (Propionitrile):
To convert ethanol to propane nitrile (propionitrile), you can follow these steps:

Dehydrate ethanol to form ethene (as described in part i):

CH3CH2OH (Ethanol) → CH2=CH2 (Ethene)

Next, perform a reaction called hydrocyanation, where you add a cyanide group (CN) to ethene. You can use hydrogen cyanide (HCN) as a source of the cyanide ion (CN-):

CH2=CH2 (Ethene) + HCN → CH3CH2CN (Propionitrile)

Now, you have successfully converted ethanol to propane nitrile (propionitrile). Please exercise caution when working with chemicals, especially in a laboratory setting, and ensure you follow proper safety protocols and have the necessary expertise and equipment to carry out these reactions safely.