Which of the following is not correct about Grignard reagent?

What is obtained when ethyl alcohol is heated with red phosphorus and $HI$?

The compound $A$ on treatment with $Na$ gives $B$,and with $PCl_{5}$ gives $C$. $B$ and $C$ react together to give diethyl ether. $A, B$ and $C$ are in the order

The effective factor in the preparation of alkene from alcohol using $Al_2O_3$ is ................ .

Compound $A, C_{8}H_{10}O,$ is found to react with $NaOI$ (produced by reacting $Y$ with $NaOH$) and yields a yellow precipitate with a characteristic smell. $A$ and $Y$ are respectively:

An alcohol $X$ $(C_4H_{10}O)$ reacts with concentrated $HCl$ at room temperature to give $Y$ $(C_4H_9Cl)$. Reaction of $X$ with copper at $573 \ K$ gives $Z$. What is $Z$?