The reagent $X$ in the reaction sequence: $(CH_3)_3C-CH=CH_2$ $\xrightarrow[THF]{X} Y$ $\xrightarrow[NaOH]{NaBH_4} (CH_3)_3C-CH(OH)-CH_3$ is:

An alcohol,$X$ $(C_5H_{12}O)$ in the presence of $Cu / 573 \ K$ gives $Y$ $(C_5H_{10})$. The reactants required for the preparation of $X$ are

What are $X$ and $Y$ in the following reactions?
$CH_2O \xrightarrow[(ii) H_3O^+]{(i) X} CH_3(CH_2)_2CH_2OH$
$Y \xrightarrow[(ii) H_3O^+]{(i) C_2H_5MgBr} CH_3CH_2C(CH_3)_2OH$

Which of the following compounds will form a $2^o$ alcohol when treated with a $\text{Grignard reagent}$ followed by hydrolysis?

Ethanol can be prepared more easily by which reaction?
$(i) \ CH_3CH_2Br + H_2O \longrightarrow CH_3CH_2OH + HBr$
$(ii) \ CH_3CH_2Br + Ag_2O \text{ (moist)} \longrightarrow CH_3CH_2OH + AgBr$

Which factor is effective in the preparation of alcohol from alkene using $Al_2O_3$?