Ethers typically undergo cleavage reactions when treated with strong acids like hydroiodic (HI) or hydrobromic (HBr) acids. In these acid-catalyzed reactions, the ether oxygen is protonated, making the ether more susceptible to nucleophilic attack, resulting in the cleavage of the C-O bond. The cleavage results in the formation of alkyl halides and alcohols or two alkyl halides if excess acid is used.