CBSE Class 10 Science 2019 · Paper 31/4/2 · Question 5

Name: Ethanol (the suffix '-ol' shows an alcohol and 'eth-' shows two carbon atoms). Molecular formula: ${\text{C}}_2{\text{H}}_5\text{OH}$, that is, ${\text{C}}_2{\text{H}}_6\text{O}$. On heating at $443$ K with excess concentrated sulphuric acid, ethanol is dehydrated to ethene: ${\text{CH}}_3{\text{CH}}_2\text{OH}\underset{\text{443 K}}{\overset{{\text{hot conc. H}}_2{\text{SO}}_4}{\to }}{\text{CH}}_2={\text{CH}}_2+{\text{H}}_2\text{O}$ Concentrated sulphuric acid acts as a dehydrating agent: it removes a molecule of water from each molecule of ethanol.