Question

When ethene is heated at \[400^\circ {\rm{C}}\] under high pressure, the product is/are
A) Carbon and \[{{\rm{H}}_{\rm{2}}}\]
B) Polyethylene
C) Acetylene and \[{{\rm{H}}_{\rm{2}}}\]
D) None of these

Answer 1

Hint: We know that polymerization is the method of polymer formation by the repetition of the units of monomers. Here, also the polymerization reaction of molecules of ethene takes place.

Complete Step by Step Answer:
Let's understand what will happen when the heating of ethene happens at the temperature of \[400^\circ {\rm{C}}\]. Polyethylene is the monomer obtained due to the heating of ethene at the temperature of \[400^\circ {\rm{C}}\]. The chemical reaction is as follows:

\[n{\rm{C}}{{\rm{H}}_{\rm{2}}} = {\rm{C}}{{\rm{H}}_{\rm{2}}} \to \mathop {{{( - {\rm{C}}{{\rm{H}}_{\rm{2}}} - {\rm{C}}{{\rm{H}}_{\rm{2}}} - )}_n}}\limits_{{\rm{Polyethylene}}} \]

Therefore, the obtained product in the heating of ethene is polyethylene.

Hence, option B is right.

Additional Information: A polymer is defined as a huge molecule composed of repetitive units of monomers. There are two ways of the polymer, such as addition and condensation polymerization. In addition, monomers possessing triple or double bonds undergo repeated addition to give a polymer. In the polyethylene formation from ethene, addition polymerization occurs. In condensation polymerization, the repeated condensation reaction between two monomers having bi or tri-functional groups produces a polymer. For example, the monomers namely 1,3-butadiene and styrene undergo condensation polymerization to give Buna-S which is a polymer.

Note: Polyethylene polymer has both positive and negative impacts on our everyday life. The positives are, it is cheaper, it is useful in grocery shopping, etc. But the cons of using polyethylene are they are non-biodegradable in nature. On burning, they release gases that are toxic in nature and are a cause of air pollution.