Step 1:
The reaction takes place with HBr or HI because these reagents are sufficiently acidic Step 2:
Iodide is a good nucleophile It attacks the least substituted carbon of the oxonium
ion formed in step 1 and displaces an alcohol molecule by SN2
 mechanism Thus, in the cleavage of mixed ethers with two different alkyl groups, the alcohol
and alkyl iodide formed, depend on the nature of alkyl groups