Which of the following is used as a solvent for the preparation of a $Grignard$ reagent?

Predict the products of the following reactions:
$(i)$ $CH_3-CH_2-CH_2-O-CH_3 + HBr \rightarrow$
$(ii)$ $\text{Ethoxybenzene} + HBr \rightarrow$
$(iii)$ $\text{Ethoxybenzene} \xrightarrow{\text{Conc. } H_2SO_4 / \text{Conc. } HNO_3}$
$(iv)$ $(CH_3)_3C-O-C_2H_5 \xrightarrow{HI}$

$(CH_3)_3C-CH(O)CH_2 + CH_3SNa \xrightarrow{C_2H_5OH} ?$
The product formed is:

The reaction of chloroethane with $Y$ gives $NaCl$ and $Z$. The reaction of one mole of $Z$ with two moles of $HI$ gives water and iodoethane. What is $Y$?

Consider the reaction of $HI$ with the following compounds:
$I$: Tetrahydropyran
$II$: Isochroman (or similar cyclic ether fused to benzene)
Which forms a di-iodide on reaction with $HI$ (excess)?

Identify the product of the following reaction: