Diethyl ether can be decomposed with:
On heating with concentrated Hydrogen iodide (HI) the C-O bond in ethers breaks forming alcohol and alkyl iodide. For example,
C2H5−O−C2H5+HI⟶C2H5−I+C2H5OH
On boiling with excess of concentrated Hydrogen iodide (HI), Alkyl iodide is formed.
C2H5−O−C2H5+2HI⟶2C2H5−I+H2O