Identify the dehydration product or products of a) ethanol, b) button-2-ol
Dehydration is a process in which an alcohol loses a molecule of water and leaves behind an alkene. The OH group is removed along with an H from any adjacent carbon atom. To work out the answer, firstly draw the structure of the alcohol in the question, and then work out the product or products.
a) Ethanol's structure is CH3CH2OH. There is only one adjacent carbon atom, and therefore only one possible product: H2C=CH2, also known as ethene. The full reaction is: CH3CH2OH ---> H2C=CH2 + H2O
b) Butan-2-ol's structure is CH3CH(OH)CH2CH3. There are two carbons adjacent to the C(OH) group, so there are two possible products: H2C=CHCH2CH3 and CH3CH=CHCH3. Both have the same molecular formulae (C4H8), but they are not the same molecule; therefore they are structural isomers.
