Final answer:
When treated with excess HX (a strong acid) and ether, the reaction involves the conversion of the ether into an alcohol and an alkyl halide. The oxygen atom in the ether is protonated by the strong acid, resulting in nucleophilic substitution.
Step-by-step explanation:
When treated with excess HX (a strong acid) and ether, the reaction that occurs is the protonation of the oxygen atom in the ether by the strong acid to form an alkoxyonium ion. The ether is converted into an alcohol and an alkyl halide through nucleophilic substitution. For example, if we treat ethyl ether (C2H5OC2H5) with excess HBr, we would obtain ethanol (C2H5OH) and bromoethane (C2H5Br).