The correct answer is:
Option 4: All cis-configuration
Natural rubber is primarily made of polyisoprene, which is a polymer composed of repeating units of isoprene (C₅H₈). The structure of natural rubber has all cis-configuration at the double bonds in the polymer chain. This means that the substituents (methyl groups) are on the same side of the polymer backbone, giving the polymer a flexible, coiled structure.
All cis-configuration: This refers to all of the isoprene units in natural rubber having the same configuration, where the two methyl groups (CH₃) are on the same side of the polymer backbone.
Cis-trans isomerism: While there is also trans-configuration, which has the methyl groups on opposite sides, natural rubber specifically has all cis-configuration in its polymer chain, which contributes to its flexibility and elasticity.
A bob of heavy mass \(m\) is suspended by a light string of length \(l\). The bob is given a horizontal velocity \(v_0\) as shown in figure. If the string gets slack at some point P making an angle \( \theta \) from the horizontal, the ratio of the speed \(v\) of the bob at point P to its initial speed \(v_0\) is :
Polymerization is a chemical reaction in which a large number of monomer molecules combine to produce a polymer. A polymerization can yield macromolecules with a linear or branching structure. They can also take the form of a three-dimensional complicated network.
Polymerization reactions are divided into two groups, namely, Addition polymerization (chain reaction) and condensation reaction (step reaction).