Predict the product(s) and provide the mechanism for each reaction below. What does each mechanism have in common?

Ethers show nucleophilic substitution reaction with alkyl halide either SN₁or SN₂ depend upon the substrate if the primary and secondary ether is given then reaction is followed by the SN₂ formation of alcohol and halide occur and if the ether is tertiary reaction followed by SN₁ formation of the alcohol and alkene occur followed by carbocation formation.

As per the reaction of 3methoxy pentane with HBr the attack of the Br ion is occur from the methyl part that is primary and the other is secondary which is more hindered and formation of methyl bromide and penta-3-ol occur and here, the primary and secondary ether is present so, reaction followed by SN₂ mechanism as shown below:

The reaction of a given compound with HI is followed by SN₂ mechanism because the group present on one side of oxygen is secondary and primary and the attack of the iodide ion (I) occurs from primary because of less hindered and formation of ethyl iodide and prop-2-ol occur as shown below:

Reaction of ethyl phenyl ether occur with HBr the react ion is procced with SN₂ mechanism as the primary ether present and attack of the Br ion is from the ethyl side due to less hindered site and formation of ethyl bromide and phenol occur as shown:

Here, presence of primary group on one side of oxygen atom and cyclopentane on other side of oxygen atom so the attack of iodine is from primary group is propyl because of less hindered reaction as reaction follow SN₂ mechanism and formation of propyl iodine and cyclo pentanol occur as shown below: