Q.
Assertion : $1,3$ - butadiene is the monomer for natural rubber.
Reason : Natural rubber is formed through anionic addition polymerization.
Solution:
$1,3$-butadiene is the monomer unit of styrene-butadiene rubber or Buna-S, for natural rubber monomer unit is isoprene. Ethylene, acrylic acid derivatives, vinyl derivatives, styrene, butadiene, isoprene and chloropene are the examples of monomers which undergo polymerisation by free radical addition polymer. Examples of anionic addition polymerisation is vinylidene cyanide, vinylidene ester derivatives of acrylonitrile, $\alpha$-methylstyrene, etc.,
