Students can read the important questions given below for Polymers Class 12 Chemistry. All Polymers Class 12 Notes and questions with solutions have been prepared based on the latest syllabus and examination guidelines issued by CBSE, NCERT and KVS. You should read all notes provided by us and Class 12 Chemistry Important Questions provid ed for all chapters to get better marks in examinations. Chemistry Question Bank Class 12 is available on our website for free download in PDF.
Important Questions of Polymers Class 12
Very Short Answer Questions
Question. Arrange the following polymers in the increasing order of their intermolecular forces :
Terylene, Polythene, Neoprene.
Answer. Neoprene < Polythene < Terylene.
Question. Write the name and structure of the monomers of the following polymer :
Buna-S
Answer. Buna-S :
Question. Name the polymer which is used for making non-stick cooking utensils.
Answer.
Question. What does the part ‘6,6’ mean in the name nylon-6, 6?
Answer. In nylon 6, 6, designation ‘6, 6’ mean that both the monomers hexamethylene diamine and adipic acid contain six carbon atoms each.
Question. Which of the following is a natural polymer?
Buna-S, Proteins, PVC
Answer. Proteins are natural polymers.
Question.
Answer. Homopolymer
Question. Based on molecular forces what type of polymer is neoprene?
Answer. Elastomer.
Question. Which of the following is a fibre?
Nylon, Neoprene, PVC
Answer. Nylon is a fibre.
Short Answer Questions
Question. Explain the following terms giving a suitable example for each:
(i) Condensation polymers
(ii) Addition polymers
Answer. Addition polymers : Th polymers formed by the addition reaction of a large number of unsaturated monomers are called addition polymers.
For example : Polythene, polystyrene.
Condensation polymers : Th polymers formed by the condensation of two or more bi functional monomers are called condensation polymers.
For example : Nylon 6,6, Bakelite.
Question. (i) What is the role of t-butyl peroxide in the polymerisation of ethene?
(ii) Identify the monomers in the following polymer :
Answer. (i) Polymerisation of ethene requires an initiator to start the polymerisation with free radical mechanism. Thus, peroxide like t-butyl peroxide decomposes to give free radical that initiates the reaction.
(ii) Hexamethylene diamine and adipic acid.
Question. Write down the structure of monomer and one use of the polymer polystyrene.
Answer.
Question. Mention two important uses of each of the following :
(i) Bakelite (ii) Nylon 6
Answer. (i) Bakellite is used for making combs, electrical switches, handles of various utensils and phonograph records.
(ii) Nylon–6 is used for making tyre cords, ropes and fabrics.
Question. Write the name of the monomers of the following polymers :
(i) Polythene (ii) Polyvinyl chloride
(iii) Bakelite
Answer. (i) Monomer of polythene is ethene.
(ii) Monomer of PVC is vinyl chloride.
(iii) Monomers of Bakelite are formaldehyde and Phenol.
Question. What is step growth polymserisation? Explain the steps involved in this process.
Answer. Step growth polymerisation involves a repetitive condensation reaction between two bi-functional monomers. Each step produces a distinct functionalised species and in independent of each other. All condensation polymerisation are step growth polymerisation.
Step : It involves condensation reaction of bifunctional molecules with elimination of smaller molecules like H2O.
Question. (i) What is the role of sulphur in the vulcanisation of rubber?
(ii) Identify the monomers in the following polymer :
Answer. Vulcanisation is a process of heating natural rubber with sulphur and an appropriate additive to modify its properties.
It gives greater elasticity and ductility. Sulphur forms cross linked network which gives mechanical strength to the rubber.
Question. Write the mechanism of free radical polymerisation.
Answer. Chain initiation :
Question. What is the difference between elastomers and fibres? Give one example of each.
Answer. (i) In elastomers polymer chains are held together by weakest intermolecular forces.
These have elastic properties. e.g. Buna-N, Buna-S.
(ii) In bres polymer chains are held together by strong intermolecular forces like hydrogen bonding.
These have high tensile strength.
e.g., Terylene, Nylon 6,6, etc.
Long Answer Questions
Question. Write the (i) structure and (ii) one use of each of the following polymers :
(a) PVC
(b) Urea-formaldehyde resin
(c) Bakelite
Answer. (i) PVC
Question. What are addition polymers? How are the two types of addition polymers different from each other? Give one example of each type.
Answer. Polymers which are formed by the repeated addition reaction of unsaturated monomer molecules are called the addition polymers.
The two types of addition polymers are :
(i) Homopolymers : The addition polymers formed by the polymerisation of a single compound are called homopolymers. e.g., polyethene.
(ii) Copolymers : The polymers made by addition polymerisation from two different compounds are known as copolymers. e.g., Buna-S
Question. Write chemical equations to form the following :
(i) Nylon-6 (b) Nylon-6,6
(iii) Polythene
Answer. (i) Nylon–6 : It is formed by self condensation of caprolactam in the presence of water.
