What products are formed when an alcohol undergoes dehydration?

When an alcohol undergoes dehydration, the key reaction involves the elimination of a water molecule (H2O) from the alcohol, resulting in the formation of an alkene. This process typically occurs under acidic conditions where the hydroxyl group (-OH) is protonated, making it a better leaving group. This leads to the formation of a carbocation intermediate, which then loses a proton from an adjacent carbon atom, resulting in a double bond (the alkene).

The formation of alkenes through dehydration is a fundamental reaction in organic chemistry, commonly used in the synthesis of various compounds. It demonstrates how alcohols can serve as precursors to alkenes, showcasing the relationship between different functional groups through conversion processes.

The other options do not accurately describe the outcome of the dehydration process of alcohols. For example, acids are not the main products; while it is possible for acid-catalyzed reactions to occur, they are not direct products of the dehydration process itself. Similarly, aldehydes and alcohols would not be produced directly from the dehydration of an alcohol. This reinforces the understanding that dehydration specifically transforms alcohols into alkenes.