(a) (i) A compound 'A' with a molecular formula of $C_2H_4O_2$ reacts with a base to give salt and water. Identify 'A', state its nature and the name of the functional group it possesses. Write chemical equation for the reaction involved.

(ii) When the above stated compound 'A' reacts with another compound 'B' having molecular formula $C_2H_6O$ in the presence of an acid, a sweet smelling compound 'C' is formed.

(1) Identify 'B' and 'C'.

(2) State the role of acid in this reaction.

(3) Write chemical equation for the reaction involved.

OR

(b) (i) Name the compound formed when ethanol is heated at $443 \text{ K}$ in the presence of conc. $H_2SO_4$ and draw its electron dot structure. State the role of conc. $H_2SO_4$ in this reaction.

(ii) What is hydrogenation ? Explain it with the help of a chemical equation. State the role of this reaction in industry.

(a) (i) The compound 'A' with a molecular formula of $C_2H_4O_2$ reacts with a base to give salt and water. The compound 'A' is acetic acid, which is a carboxylic acid. The functional group it possesses is the carboxyl group (-COOH). The chemical equation for the reaction involved is:

$$CH_3COOH + NaOH \rightarrow CH_3COONa + H_2O$$

(ii) (1) The compound 'B' having molecular formula $C_2H_6O$ is ethanol. The sweet smelling compound 'C' formed when 'A' reacts with 'B' in the presence of an acid is ethyl acetate.

(2) The role of acid in this reaction is to act as a catalyst.

(3) The chemical equation for the reaction involved is:

$$CH_3COOH + C_2H_5OH \xrightarrow{H^+} CH_3COOC_2H_5 + H_2O$$

OR

(b) (i) The compound formed when ethanol is heated at $443 \text{ K}$ in the presence of conc. $H_2SO_4$ is ethene. The electron dot structure of ethene is:

$$H_2C = CH_2$$

The role of conc. $H_2SO_4$ in this reaction is to act as a catalyst.

(ii) Hydrogenation is the process of addition of hydrogen to an unsaturated compound in the presence of a catalyst. The chemical equation for the reaction involved is:

$$C_2H_4 + H_2 \xrightarrow{Ni} C_2H_6$$

The role of this reaction in industry is to convert unsaturated compounds into saturated compounds, which are more stable and have a higher melting point.