How is chlorobenzene prepared in the laboratory and on a large scale.

With the help of Cahn-Ingold-Prelog sequence indicate the priority sequence for the following groups.

$-{\mathrm{CH}}_3, -{\mathrm{CH}}_2-{\mathrm{CH}}_3, -\mathrm{CH}{\left({\mathrm{CH}}_3\right)}_2, -\mathrm{C}{\left({\mathrm{CH}}_3\right)}_3$

With the help of Cahn-Ingold-Prelog sequence indicate the priority sequence for the following groups.

$\mathrm{OH}, \mathrm{D}, \mathrm{H}, \mathrm{CHO}, {\mathrm{CH}}_2\mathrm{OH}$

Assign $\left(\mathrm{R}\right)$ and $\left(\mathrm{S}\right)$ configuration for the following compounds: