Vulcanisation makes rubber ______________.
(i) more elastic
(ii) soluble in inorganic solvent
(iii) crystalline
(iv) more stiff
The answer is the option (i, iv). Vulcanisation is a chemical process wherein rubber is heated with Sulphur to form cross-links between rubber molecules. The process is carried to improve the physical properties like elasticity of natural rubber. It makes the rubber stiffer.