Which of the following are synthetic rubbers? (i) Terylene (ii) Buna-S (iii) Buna-N (iv) Neoprene (v) Polyacrylonitrile

• A

  (i), (ii) and (iii)
• B

  (ii), (iv) and (v)
• Correct answer
  C

  (ii), (iii) and (iv)
• D

  (i), (ii) and (iv)

Solution

$\because$ Buna-S is $n \mathrm{CH}_2=\mathrm{CH}-\mathrm{CH}=\mathrm{CH}_2$ $(1,3$-butadine $)+n \mathrm{C}_6 \mathrm{H}_5-\mathrm{CH}=\mathrm{CH}_2$ (styrene); Buna- $\mathrm{N}$ is $n \mathrm{CH}_2=\mathrm{CH}-\mathrm{CH}=\mathrm{CH}_2$

All these are synthetic rubber. Hence, option (c) is the correct answer, i.e. (ii), (iii) and (iv).

Hence, the correct answer is option: 'C'.