Question

An organic Compound (A) is widely used as a preservative in a pickle and has a molecular formula \[{{\text{C}}_{\text{2}}}{{\text{H}}_{\text{4}}}{{\text{O}}_{\text{2}}}\]. This compound reacts with ethanol to form a sweet smelling compound (B)
A.Identify the compounds A and B
B.Name the process and write the corresponding chemical equation

Answer 1

Hint:It is a carboxylic acid to which methyl group is attached.The other name of compound (A) formed is Vinegar, and vinegar is used as preservative in pickle. Molecular Weight of acetic acid is \[{\text{60}}{\text{.052g/mol}}\].

Complete step by step answer:
We know Ethanoic acid is used as a solvent and as a Vinegar in the food Industry, vinegar is the dilute solution of acetic acid. Its structural formula is \[{\text{CH3COOH}}\], therefore compound (A) is Acetic acid.
            Also when compound (A) reacts with Ethanol it produces sweet smelling compound which is an ester i.e.,
\[{\text{CH3COOH}}\]\[ + {{\text{C}}_{\text{2}}}{{\text{H}}_{\text{5}}}{\text{OH}}\mathop \leftrightarrows \limits^{{H^ + }} {\text{C}}{{\text{H}}_{\text{3}}}{\text{COO}}{{\text{C}}_{\text{2}}}{{\text{H}}_{\text{5}}} + {{\text{H}}_2}{\text{O}}\]
Hence the compound (B) formed is Ethyl Ethanoate.

To get ethanoic acid from ethyl ethanoate hydrolysis process is followed with the chemical equation
${\text{C}}{{\text{H}}_{\text{3}}}{\text{COO}}{{\text{C}}_{\text{2}}}{{\text{H}}_{\text{5}}}{\text{ + }}{{\text{H}}_{\text{2}}}{\text{O}}\xrightarrow{{{{\text{H}}^{\text{ + }}}}}{\text{C}}{{\text{H}}_3}{\text{COOH + }}{{\text{C}}_2}{{\text{H}}_5}{\text{OH}}$

Additional Information- Ethanoic acid, also called acetic acid as its common name. . It is used in making a polymer called acetate rayon.The structure of ethanoic acid is

 

Molecular Weight: \[{\text{62}}{\text{.037 }}\dfrac{{\text{g}}}{{{\text{mol}}}}\]

Ethanoic acid is when it gets undiluted it is known as glacial acid.


Note:
Ethanoic acid, also called acetic acid as its common name, is a weak acid distinguishable by its sharp, vinegar like smell .
In Chemistry, after every reaction has thus formed will always give a foul smell, Only Ester is a compound in general which gives a fruity smell/pleasant smell. It is also used in the food industry as an acidity regulator.