Which alkyl halide from the following pair would you expect to react more rapidly by an ${\mathrm{S}}_{\mathrm{N}}2$ mechanism? Explain your answer.

Name the following halide according to IUPAC system and classify it as alkyl, allyl, benzyl (primary, secondary, tertiary), vinyl or aryl halide:

$\mathrm{C}{\mathrm{H}}_3\mathrm{C}{\mathrm{H}}_2\mathrm{C}\mathrm{H}\left(\mathrm{C}{\mathrm{H}}_3\right)\mathrm{C}\mathrm{H}\left({\mathrm{C}}_2{\mathrm{H}}_5\right)\mathrm{C}\mathrm{l}$

Name the following halide according to IUPAC system and classify them as alkyl, allyl, benzyl (primary, secondary, tertiary), vinyl or aryl halides:

$\mathrm{C}{\mathrm{H}}_3\mathrm{C}{\mathrm{H}}_2\mathrm{C}{\left(\mathrm{C}{\mathrm{H}}_3\right)}_2\mathrm{C}{\mathrm{H}}_2\mathrm{I}$

Name the following halide according to IUPAC system and classify it as alkyl, allyl, benzyl (primary, secondary, tertiary), vinyl or aryl halide:

${\left(\mathrm{C}{\mathrm{H}}_3\right)}_3\mathrm{C}\mathrm{C}{\mathrm{H}}_2\mathrm{C}\mathrm{H}\left(\mathrm{B}\mathrm{r}\right){\mathrm{C}}_6{\mathrm{H}}_5$

Name the following halide according to IUPAC system and classify it as alkyl, allyl, benzyl (primary, secondary, tertiary), vinyl or aryl halide:

$\mathrm{C}{\mathrm{H}}_3\mathrm{C}\mathrm{H}\left(\mathrm{C}{\mathrm{H}}_3\right)\mathrm{C}\mathrm{H}\left(\mathrm{B}\mathrm{r}\right)\mathrm{C}{\mathrm{H}}_3$