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Xam Idea Class 12 Chemistry Chapter 15 Solutions: Polymers

Our Xam Idea Class 12 Chemistry Solutions Chapter 15 – Polymers are drafted in a manner to help you understand the use of chemical reactions for making polymers and importance of polymers. These polymers are essential parts of human lives. Our Xam Idea Solutions explain the concepts clearly and help you develop a strong base in this topic. These solutions follow the exact guidelines given by CBSE and NCERT.

Part A of our solutions contains detailed explanations of all fundamental concepts of this chapter, followed by answers to all the questions. The questions are based on memory and higher-order thinking skills. Some questions are very short answer questions, some are short answer type questions, and some are long answer type questions. Part B of our solutions contains elaborated answers to all model questions papers based on the latest CBSE exam format. Here you will also find solutions to previous year’s question papers. Our Solutions give you ample practice to perfect your conceptual understanding.

This chapter explains the terms monomer, polymer and polymerisation and encourages you to understand their uses in daily life. You further learn about distinguishing between different classes of polymers and types of polymerisation processes. You also learn about the mechanism of formation of polymers from mono- and bifunctional monomer molecules. This chapter further describes the preparation of some important synthetic polymers and their properties along with uses and importance of polymers in daily life. You come to know the names of various polymers and their constituent monomers.

Important Topics for Xam Idea Class 12 Chemistry Chapter 15 – Polymers

Xam Idea Class 12 Chemistry Solutions Chapter 15 – Polymers cover all the concepts given in the chapter. They enable you to delve deep into the concepts discussed here. The outline of the concepts covered in this chapter has been given below.

  • Classification of Polymers

This part of the chapter tells you that polymers are macromolecules formed by joining of repeating units known as monomers. The process of joining the monomers to get polymers is called polymerisation. Polymers can be classified into three categories based on their source — natural (cellulose), semi-synthetic (rayon) and synthetic polymers (Teflon).

Here you will also learn that based on the structure of polymers, polymers are divided into the linear (high-density PVC), branched-chain (low-density PVC) and cross-linked or network polymers (bakelite). Polymers can also be classified depending upon the process through which they are prepared. Our Xam Idea Class 12 Chemistry Solutions Chapter 15 – Polymers gives you all the critical knowledge about this topic.

Further, you learn the different processes of polymerisation here. Addition polymers are formed by repeated addition of monomer molecules to give a homopolymer. Its example is polythene. Two different types of monomers combine to give a copolymer. An example is Buna-N.

This section also teaches you that the condensation polymers are formed by repeated condensation of two different multifunctional monomers; its example is Nylon 6,6. Another way to classify polymers is on the basis of intermolecular forces, like elastomers (Buna-S), fibres (polyester), thermoplastic polymers (polystyrene) and thermosetting polymers (bakelite). Our Xam Idea Class 12 Chemistry Solutions Chapter 15 – Polymers help you learn all the examples of polymers and their monomers.

  • Types of Polymerisation Reactions

This portion of the chapter tells you about two broad types of polymerisation reactions –

  • chain growth or addition polymerisation and
  • condensation or step-growth polymerisation

In the first type, molecules of same monomer or different monomers add together in a big number to give polymer. This takes place in different levels leading to growth in chain length, and each step produces reactive intermediate species for use in the next stage of the growth of the chain. In this type of polymerisation, free radical mechanism of chain growth is the most common one, and few examples are polythene, Teflon, polyacrylonitrile etc. Xam Idea Class 12 Chemistry Solutions Chapter 15 – Polymers help you to learn these types of polymerisation in a comprehensive manner.

It further tells you that condensation polymerisation reactions are shown by the interaction of bi- or polyfunctional monomers containing -NH2, -OH and -COOH groups. Here you will also learn that this type of polymerisation generally involves a repetitive condensation reaction between two bi-functional monomers and the product of each stage is again a bi-functional species. The sequence of condensation goes on like this. As each step produces a distinct functionalised species and is independent of each other, this process is also called as step-growth polymerisation.

Further, you come to know that step-growth polymerisation proceeds through the elimination of some small molecules like H2O, CH3OH, among others. Examples of step-growth polymers are polyamides (Nylon 6,6 and Nylon 6), polyesters (dacron or terylene), phenol-formaldehyde polymer (bakelite) and melamine-formaldehyde polymers. Our Xam Idea Class 12 Chemistry Solutions Chapter 15 – Polymers gives you helpful tips to remember these effectively.

Next, this chapter talks about co-polymerisation where a mixture of more than one type of monomers is allowed to polymerise to give a copolymer, an example is a butadiene-styrene polymer. This part further tells you that rubber is a naturally occurring polymer (cis 1,4-polyisoprene) with elastic properties. This part of the chapter also tells you about synthetic rubbers Neoprene and Buna-N, along with the process of their preparation. Vulcanisation of rubber is the process of heating raw rubber mixed with sulphur and an additive between 373 K to 415 K. This is done to improve the physical properties of rubber-like elasticity, strength etc.

  • Biodegradable Polymers

This part of the chapter tells that most of the polymers are resistant to natural degradation processes existing in the environment. Polymers which are degraded by microorganisms within a suitable period are known as biodegradable polymers, and their decomposition products are harmless for the environment. This leads to the accumulation of waste materials causing environmental problems. PHBV and Nylon 2-nylon 6 are biodegradable man-made polymers. Our Xam Idea Class 12 Chemistry Solutions Chapter 15 – Polymers covers all the important aspects of this portion and helps you score good marks in class 12 board exam.

Exercise Discussion for Xam Idea Class 12 Chemistry Chapter 15 – Polymers

After learning all the concepts, you are advised to solve all the questions given at the end of the chapter. Some questions are very short answer questions, and some are short answer type questions.

The questions test your memory skills, analytical skills, understanding of the concepts and higher-order thinking skills and are divided into objective type questions, fill in the blanks type questions, match the columns type questions and assertion-reasoning type questions. Given below is a summary of the questions in this chapter.

This chapter has 21 VSAQs based on the names of terms used in this chapter, identification of monomers of given polymeric structures, the purpose of vulcanisation, types of polymers and polymerisation, mechanism of free radical polymerisation, intermolecular forces in rubber, identification of monomers, a biodegradable polymer and uses of polymers in daily life.

Next, there are 29 SAQs which ask you about different monomers, processes of polymerisation, names of polymers, intermolecular forces in polymers, the definition of the polymerisation process, mechanism of free radical polymerisation, synthesis of dacron. There are direct questions based on the source of polymers, the explanatory question on the functionality of monomer, explanatory question on the definition of polymerisation. All of these questions have been answered systematically in our Xam Idea Class 12 Chemistry Solutions Chapter 15 – Polymers.

These questions give you an ample amount of practice on different concepts learnt about polymerisation. The part B of our solutions has several fully solved model papers and previous year’s question papers. You are advised to solve them so that you get the exact idea of how questions are framed for exams. These give you an overall idea of types of questions asked in your board exams and the correct way to prioritise and answer questions to score maximum marks in your exams.

Benefits of Xam Idea Class 12 Chemistry 15 – Polymers

The important benefits of learning and revising from our Xam Idea Class 12 Chemistry Solutions Chapter 15 – Polymers are given below. These advantages make our solutions the best study material.

  • They help you to become thorough with the fundamental concepts related to polymers.
  • They are to the point, fully accurate and facilitate speedy and effective learning.
  • Our solutions give you the step by step process to solve every question to help you learn easily.
  • These methodical solutions work as quick revision notes during exams and help you learn effectively and retain maximum.
  • They cover a wide range of question types important from exam point of view
  • They have been designed to clear all your doubt and improve your retention rate.
  • They have been solved using the best methods of solving the problems.
  • Our solutions include detail explanations, relevant examples, and illustrative diagrams to help you learn efficiently.
  • They help you build a strong conceptual foundation.
  • Our solutions have been designed to make learning fun, interesting, engaging, interactive, efficient.