Question

How will you obtain:
A.Methanol from acetic acid
B.Ethyl alcohol from ethene
C.Acetic acid from ethyne

Answer 1

Methanol is the simplest alcohol which is also called methyl alcohol. It is used as a solvent for paints and varnishes. Ethyl alcohol is prepared from ethene by addition of water which is also called hydration of alkenes.

Complete step by step answer:
A)To prepare methanol from acetic acid-
When acetic acid reacts with a $C{H_3}ONa$ then methanol and sodium acetate are formed. The reaction is given as-
$C{H_2}COOH + C{H_3}ONa \to C{H_3}COONa + C{H_3}OH$
In this reaction the stronger acid displaces the weaker acid from the salt of the weaker acid.
B)To prepare ethyl alcohol from ethene-
When water is added to ethene in presence of mineral acid, ethyl alcohol is produced. The reaction is given as-
$C{H_2} = C{H_2} + {H_2}O\xrightarrow{{{H^ + }}}C{H_3} - C{H_2}OH$
In this reaction, water breaks into ${H^ + }$ and $O{H^ - }$. Then one part of water attaches itself to one carbon atom and the other part to the second atom due to which the double bond between Carbon and carbon atoms converts to a single bond.
C)To prepare acetic acid from ethyne-
When ethyne reacts with water in presence of $HgS{O_4}$ it gives acetaldehyde which in oxidation gives acetic acid. The reaction is given as-
$HC \equiv CH + {H_2}O\xrightarrow[{HgS{O_4}}]{{{H^ + }}}{H_2}C = CHOH\xrightarrow{{\operatorname{Re} arrangement}}C{H_3}CHO\xrightarrow{O}C{H_3}COOH$
In this reaction, water breaks into ${H^ + }$ and $O{H^ - }$. Then one part of water attaches itself to one carbon atom and the other part to the second atom due to which the triple bond between Carbon and carbon atoms converts to double bond. Then on rearranging the molecule, we get acetaldehyde. This acetaldehyde is oxidized and acetic acid is formed.

Note:
The uses of acetic acid are-
-The acetic acid is used as an antiseptic as it has antibacterial properties.
-It is used as a major constituent of vinegar.
-It is used in preparation of many chemical compounds like VAM( vinyl acetate monomer).
-It is used as a solvent for polar molecules.