a. Given the major products formed by heating the following ethers with conc. HI with metioning `SN^(-1)` or `SN^(-2)` mechanism.
i. (1- Propoxy propane)
ii. `Ph--O--Me` (Methoxy benzene)
iii. `Ph--CH_(2)--O--Et` (benzyl ethyl ether)
iv. (1-Ethoxy-2-methyl butane)
v. (2-Propoxy-2-methyl butane)
vi. `PhCH_(2)OPh` (Benzyl phenyl ether)
vii. (Tetrahydrofuran, THF)
b. Given the products of the above ethers with excess of HI.
c. Why does `SN^(-2)` cleavage occur at a faster rate with HI than with HCI ?

Explanation

a. i. Symmetrical ether `1^(@)` R groups, `SN^(-2)`

ii. Phenol `(Ph--OH) + MeI (SN^(2))` (`1^(@)` R groups)
iii. `overset (PhCH_(2)I` underset (Benzyl iodide)` + `overset (EtOH) underset (Ethanol)` (stability of benzyl `C^(o+))` `(SN^(1))`
iv. (RI with smaller alkyl gp. O atom is joined both side with `1^(@)` C atom `SN^(2)`)
v.
`overset (PhCH_(2)I) underset (Benzyl iodide)` + `overset (PhOH) underset (Phenol)` (Stability of benzyl `C^(o+) SN^(1)`)
vii.
i. (Iodopropane)
ii. PhOH + MeI (PhoH does not undergo ArSN reaction unless activated EWG)
iii. `PhCH_(2)I + EtI` (Benzyl iodide + Ethyl iodide)
iv.
v.
`overset (PhCH_(2)I + PhOH) underset (Phenol doesn't undergo ArSN reactions.)`
The transfer of `H^(o+)` to ROR' is grater with HI, which is a stronger acid, than with HCI. Moreover, `I^((-))` being a better nucleophile than `CI^((-))`, it reacts art faster rate in step 2 of the mechanism of the reaction.