(a) Write the name and structure of an organic compound 'X' having two carbon atoms in its molecule and its name is suffixed with '— ol'.

(b) What happens when 'X' is heated with excess concentrated sulphuric acid at 443 K? Write chemical equation for the reaction stating the conditions for the reaction. Also state the role played by concentrated sulphuric acid in the reaction.

(c) Name and draw the electron dot structure of hydrocarbon produced in the above reaction.

(a) An organic compound 'X' with two carbon atoms whose name ends with "-ol" is ethanol.

• Molecular formula : C₂H₅OH.
• Structural formula : CH₃—CH₂—OH.

(b) This gives dehydration (elimination) of ethanol to form ethene (C₂H₄) as shown below :

$\text C$2 \text H5 \text {OH} \xrightarrow [443\ \text K]{\text {conc. H}2\text{SO}4} \text C2 \text H4 + \text H_2 \text O

Role of conc. H₂SO₄ :

• Acts as a dehydrating agent (removes water).
• Acts as an acid catalyst, helping protonate ethanol and promote loss of water to form the alkene.

(c)

• Name of the compound formed : Ethene (also called ethylene)
• Molecular formula : C₂H₄

Electron-dot (Lewis) structure of ethene is shown below :