What is produced when ethanol undergoes dehydration with a catalyst?

• A. Ethene
• B. Ethane
• C. Ethanol
• D. Ethyl ethanoate

Answer: (A)

Dehydration of an alcohol with a catalyst is an elimination process that removes a water molecule to form an alkene. In ethanol, the -OH group is protonated by the acid, turning into a good leaving group as water. When water leaves, a hydrogen from the adjacent carbon is removed, creating a C=C double bond and yielding ethene. The reaction can be written as CH3-CH2-OH → CH2=CH2 + H2O, with the acid catalyst (like concentrated sulfuric acid) and heat driving the process. Ethane would come from adding hydrogen (hydrogenation), not removing water. Ethyl ethanoate would form by esterification with a carboxylic acid, not dehydration.