Rank the following compounds in order of decreasing rate of solvolysis with aqueous ethanol (fastest $\to$ slowest):
$(1)$ $CH_2=C(CH_3)Br$
$(2)$ $1-bromo-1-methylcyclohexane$
$(3)$ $CH_3-CH(Br)-CH_2-CH(CH_3)_2$

$A$ solution of $1$-chloro-$1$-phenylethane in toluene undergoes direct racemization in the presence of a small amount of $SbCl_5$ due to the formation of:

$A$ 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?

Explain the stereochemistry of $S_{N}2$ reaction with a suitable example.

Given below are two statements $:$
Statement $(I) :$ Alcohols are formed when alkyl chlorides are treated with aqueous potassium hydroxide by elimination reaction.
Statement $(II) :$ In alcoholic potassium hydroxide,alkyl chlorides form alkenes by abstracting the hydrogen from the $\beta-$carbon.
In the light of the above statements,choose the most appropriate answer from the options given below $:$

Which of the following is added to chloroform to slow down its aerial oxidation in the presence of light?