Which of the following is a synthetic rubber.

The CORRECT match of monomer precursor in Column A to polymer in Column B is

	Column A		Column B
$\mathrm{P}$		$\mathrm{i}$	Melamine
$\mathrm{Q}$		$\mathrm{ii}$	Novolae
$\mathrm{R}$		$\mathrm{iii}$	Neoprene
$\mathrm{S}$		$\mathrm{iv}$	Buna-N

Give the chemical reaction for the preparation of Nitrile rubber. Also mention its two properties and two uses.

Write the structure of monomer used for getting the Buna-S polymer.