Identify the reagent $A$ in the following conversion.
Alkyl halide $\xrightarrow{A}$ Alkyl nitrite

$CH_3CH_2CH_2OH$ $\xrightarrow{PCl_5} A$ $\xrightarrow{\text{alcoholic } KOH} B$. The final product $B$ is ...... .

The rate of $S_N2$ reaction will be negligible in:

Consider the following reaction:
$CH_3-CH_2-CH(Br)-CH_3 \xrightarrow{alc. KOH, \Delta} CH_3-CH_2-CH=CH_2 (I) + CH_3-CH=CH-CH_3 (II)$
Which of the following statements are correct?
$a.$ $I$ is the major product of the reaction
$b.$ $II$ is the major product of the reaction
$c.$ Formation of $I$ is in accordance with Saytzeff's rule
$d.$ $II$ is more stable because it is more substituted

Which of the following is the most reactive towards $S_{N}1$ mechanism?

$A$ bottle containing $C_6H_5I$ and $C_6H_5CH_2I$ has lost its label. To identify them,samples $A$ and $B$ are taken in separate test tubes and boiled with $NaOH$ solution. Finally,the solution in each test tube is acidified with dilute $HNO_3$ and then a few drops of $AgNO_3$ solution are added. Substance $B$ gives a yellow precipitate. Which statement is correct for this process?