Question

Starting from ethanoic acid, how will you prepare (i) methane (ii) ethane?

Answer 1

Hint: The molecular formula of Ethanoic acid is ${{C}_{2}}{{H}_{4}}{{O}_{2}}$ . Acetic also called as ethanoic acid. Directly we cannot prepare methane and ethane from ethanoic acid. First we have to convert ethanoic acid into sodium salt and then we can prepare methane and ethane from acetic acid.

Complete answer:
- In the question it is asked to prepare ethane and methane from ethanoic acid.
- The common step in the preparation of methane and ethane from ethanoic acid is as follows.
\[C{{H}_{3}}COOH+NaOH\to C{{H}_{3}}COONa+{{H}_{2}}O\]
- In the above reaction acetic acid reacts with sodium hydroxide and forms sodium acetate and water as the products.
(i) Preparation of methane:
- The formed sodium acetate reacts with sodium hydroxide on distillation and produces methane as the product and the chemical reaction is as follows.
\[C{{H}_{3}}COONa+NaOH\to C{{H}_{4}}+N{{a}_{2}}C{{O}_{3}}\]
- In the above chemical reaction sodium acetate reacts with sodium hydroxide and forms methane and sodium carbonate as the products.
(ii) Preparation of ethane:
On electrolysis sodium acetate forms ethane as the product and the chemical reaction is as follows.
\[C{{H}_{3}}COONa+2{{H}_{2}}O\to {{C}_{2}}{{H}_{6}}+NaOH+{{H}_{2}}+C{{O}_{2}}\]
- In the above chemical reaction with ethane, sodium hydroxide, hydrogen gas and carbon dioxide are going to form as the products.

Note:
The formed sodium carbonate (solid precipitate) can be easily removed after distillation because it settles at the bottom of the distillation flask as a solid. Electrolysis is a process of decomposition of ionic compounds into their respective chemicals by passing a direct current through the chemicals in dissolved form.