The reaction $RCl + NaI \xrightarrow{\text{Acetone}} R-I + NaCl$ is known as:

$A$ 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?

Reaction of $(R)-2$-butanol with $p$-toluenesulphonyl chloride in pyridine followed by $LiBr$ gives:

Compare the rate of $E_2$ reaction for the following compounds:
$a$: $(CH_3)_3C-Br$
$b$: $CH_3-CH(Br)-CH_3$
$c$: $CH_3-CH_2-Br$

Identify the major product $X$ in the following reaction: $CH_3-CH_2-CHF-CH_3 \xrightarrow[\Delta]{alc. KOH} X$ (Major)

Grignard reagent is not prepared in aqueous medium but prepared in ether medium because the reagent