Question

Which of the following is not a polymer?

Answer 1

Hint: Polymer consists of repeating structures called monomers. Polymer is a compound consisting of one or more units of monomers joined either by condensation or free radical mechanism. The compound which does not consist of repeating molecules joined together and instead consists of molecules in a lattice will not be a polymer and the correct answer.

Complete step-by-step answer:
Polymerization is a process of reacting monomer molecules together in a chemical reaction to form long polymer chains .
In chemical compounds, polymerization can occur by various types of reaction mechanisms that vary in complexity due to the functional groups present in the reactants and the steric effects that are present.
In simple polymerizations, alkenes form polymers through relatively simple free radical reactions; in contrast, reactions involving substitution at a carbonyl group require more complex synthesis due to the way in which reactants polymerize and the steric hindrance offered by neighboring groups.
Alkanes are polymerized, with the help of strong mineral acids.
Polymerization is divided into 2 types based on the number of monomers used, namely homo polymerisation and copolymerisation.
The polymerisation reaction involving a single monomer is known as homo polymerisation.
Copolymerisation is the type of polymerisation reaction involving more than one type of monomer. The number of monomers involved in the reaction Is usually 2.
Ice is the solid form of water. It is not a polymer as it is just a different state of matter of water.
Starch is an organic polymer with the monomer being glucose units.
Protein is a polymer of various types of amino acids.
Cellulose is also an organic polymer with the monomer being glucose units. However, the linkage in cellulose is different from that of starch polymer.


Therefore, the correct answer is option (A).


Note: The two main classes of polymerisation reaction mechanisms are step-growth and chain growth polymerisation.
In step-growth polymerisation, the pairs of reactants combine at each step to form a longer polymer chain. The average molar mass increases slowly, long chains are formed only at the end of the reaction.
However, in case of chain growth polymerisation the addition of monomer to the growing chain with active centre (like free radical, cation, anion) is the chain extension step. Long chains are formed from the starting of the reaction only.