The reaction of chloroform with concentrated $HNO_3$ yields ........

Predict the order of reactivity of the following four isomers towards $S_{N}2$ reaction.
$(I)$ $CH_{3}CH_{2}CH_{2}CH_{2}Cl$
$(II)$ $CH_{3}CH_{2}CH(Cl)CH_{3}$
$(III)$ $(CH_{3})_{2}CHCH_{2}Cl$
$(IV)$ $(CH_{3})_{3}CCl$

The major product of the following reaction is: $CH_3-CH(Br)-CH_2-CH(Br)-CH_2-CH_3 \xrightarrow[heat]{KOH, CH_3OH}$

Which of the following compounds will not undergo Friedel-Crafts reaction with benzene?

The reaction of $n$-propyl bromide with ethanolic potassium hydroxide $(KOH)$ produces ...... .

Which among the following compounds will undergo the fastest $S_{N}2$ reaction?