NCERT Solutions for Class 8 Science Chapter 3 Synthetic Fibres and Plastics

 

NCERT solutions for class 8 science chapter 3 Synthetic Fibres and Plastics- From ancient times, humans are using fabrics for wearing and for other purposes also. The smallest unit of fabric is called fiber. These fibers may come from natural sources like cotton, jute etc or may be invented in laboratories by using chemical reagents. In this chapter, along with CBSE NCERT solutions for Class 8 Science Chapter 3 Synthetic Fibres and Plastics, you will get to know about different types of synthetic fibers. This chapter also talks about the processes involved in the formation of these fibers in laboratories. After studying the chapter thoroughly you will be able to attempt the exercise of NCERT textbook and get correct solutions of NCERT for class 8 science chapter 3 Synthetic Fibres and Plastics. Learning would be easier if you have CBSE NCERT solutions for Class 8 Science Chapter 3 Synthetic Fibres and Plastics within your reach. You can also check out the solutions of NCERT for other chapters in science or even for other subjects by using the given links on this page.

  • What are Synthetic fibres?

Fibres are of two types i.e. natural fibres and synthetic fibres.

Synthetic fibres are those fibres which are produced in laboratories using chemicals by man. Thus, they are also called man-made fibres. Synthetic fibres are made in such a way that small units join together to form them. These small units that are joined together are called monomers. After joining they form polymers which make up the synthetic fibres. Have you ever thought when we can get fibres from natural sources then why do we need to produce them in laboratories? Try to answer this question once you have read the chapter and attempted NCERT solutions for class 8 science chapter 3 synthetic fibres and plastics.

  • Types of synthetic fibres

Every day you use so many different types of synthetic fibres such as rayon, nylon, polyester and acrylic. In NCERT science class 8 chapter 3, you will study about the various characteristics of the above mentioned synthetic fibres. So what do you think “are synthetic fibres better natural fibres”?  After reading chapter 3 synthetic fibres and plastics, you will be able to find out the answer to this question.

Each of you must have used objects made up of plastic. In NCERT class 8 chapter 3 Synthetic fibres and plastics, you will get to know the details about what is plastic, how it is made, what are its different characteristics and how they are useful to humans. Have you ever thought why plastic bags are now banned on grocery shops? Why everybody prefers to use paper cups and not plastic cups? You can get answers to these questions in NCERT solutions for class 8 science Chapter 3 Synthetic fibres and plastics.

In the end, there are insights of biodegradable and non-biodegradable substances in your NCERT textbook science chapter 3. Do you segregate your waste when you dispose of them? If yes, then how do you segregate them? Why do we see blue, red, yellow and green dustbins on roads? You will be able to answer all these questions once you have gone through NCERT solutions for class 8 science chapter 3 Synthetic fibres and plastics.

 

 

NCERT class 8 science chapter 3 Synthetic fibres and plastics- Topics

Different topics and subtopics are there in NCERT science class 8 Ch 3. These topics that you will get to learn  in this chapter are :

3.1 What are synthetic fibres

3.2 Types of synthetic fibres

3.2.1 Nylon

3.2.2. Rayon

3.2.3 Polyester and acrylic

3.3 Characteristics of synthetic fibres

3.4 Plastic

3.5 Plastics as materials of choice

3.6 Plastics and the environment

NCERT grade 8 science chapter 3 Synthetic fibres and plastics- Preparation tips

In order to prepare this chapter, write your own NCERT class 8 chapter 3 notes. Once you are done with the chapter reading and have gone through this introduction to synthetic fibres and plastics, you can try solving NCERT class 8 chapter 3 synthetic fibres and plastics worksheets. For better practice, attempt as many NCERT quizzes for science chapter 3 as possible. All the students ahould practice more and more question like the ones given below:

Q. Most women do not prefer to wear polyester clothes while working in the kitchen. Give reason

Ans.Polyester is a synthetic fabric that melts on heating. So if women wear polyester in the kitchen there are chances that on heating, it will melt and stick to the body causing destruction. Hence most women do not prefer to wear polyester clothes while working in the kitchen. 

NCERT solutions for class 8 science chapter 3 Synthetic fibres and plastics

Synthetic Fibres and Plastics Excercise:

Q1. Explain why some fibres are called synthetic.

Answer:

Some fibres are made by human beings and not obtained from plants and animals. These fibres are obtained by chemical processing of petrochemicals..That is why some fibres are called synthetic or man-made fibres. Few examples are: Nylon, Polyester and Acrylic.

Q 2. Mark ( tick ) the correct answer.

Rayon is different from synthetic fibres because

(a) it has a silk-like appearance.

(b) it is obtained from wood pulp.

(c) its fibres can also be woven like those of natural fibres.

Answer:

(b) is the correct option.

Rayon also called artificial silk is a man-made fibre, but it is obtained from a natural source, wood pulp. its fibres can also be woven like those of natural fibres

Q3. Fill in the blanks with appropriate words.

(a) Synthetic fibres are also called __________ or __________ fibres.

(b) Synthetic fibres are synthesised from raw material called __________ .

(c) Like synthetic fibres, plastic is also a __________ .

Answer:

(a) Synthetic fibres are also called man-made or artificial fibres.

(b) Synthetic fibres are synthesised from a raw material called petrochemicals.

(c) Like synthetic fibres, plastic is also a polymer.

Q4. Give examples which indicate that nylon fibres are very strong.

Answer:

Nylon fibres are used for making parachutes and ropes for rock climbing. These examples indicate that nylon fibres are very strong. Moreover, Nylon fibre is actually stronger than steel wire.

Q5. Explain why plastic containers are favoured for storing food.

Answer:

Plastic containers are favoured for storing a food item, water, milk etc. because of the following reasons:

(a) Plastics are lightweight

(b)Plastics are cheaper than metals

(c) Plastics are very strong and are easy to handle.

Q6. Explain the difference between thermoplastic and thermosetting plastics.

Answer:

Thermoplastics Thermosetting Plastics
It gets deformed easily on heating and bends easily. It does not get deformed on heating
The original shape is not retained     The original shape is retained
Examples: Polyethene and PVC        Examples: Bakelite and melamine

Q7.(a) Explain why the following are made of thermosetting plastics.

    Saucepan handles

Answer:

Thermosetting plastics are those plastics which retain their shape on heating. Saucepan handles are made of thermosetting plastic like Bakelite because it is a poor conductor of heat. Hence, it prevents the hand from getting burned. 

Q7. Explain why the following are made of thermosetting plastics.

(b) Electric plugs/switches/plugboards

Answer:

Thermosetting plastics are used to make electrical switches because these are a poor conductor of heat and electricity. Hence, they are good insulators and prevents from getting electric shocks.plugboards

Q8. Categorise the materials of the following products into ‘can be recycled’ and ‘cannot be recycled’.

telephone instruments, plastic toys, cooker handles, carry bags, ball point pens, plastic bowls, plastic covering on electrical wires, plastic chairs, electrical switches.

Answer:

Can be Recycled         Cannot be Recycled
Plastic toys Telephone instruments
Carry bags Cooker handles
Ball point pens Electrical switches
Plastic bowls  
Plastic covering on electrical wires  
Plastic chairs  

 

Q9. Rana wants to buy shirts for summer. Should he buy cotton shirts or shirts made from synthetic material? Advise Rana, giving your reason.

Answer:

Rana should buy cotton shirts and not synthetic shirts for summer.

Because synthetic shirts are not good absorber of moisture as compared to cotton. Hence, during summer, cotton being a good absorber of moisture will let the sweat evaporate from the body.

Q10. Give examples to show that plastics are noncorrosive in nature.

Answer:

The cleaning chemicals used at home are stored in plastic bottles, instead of metallic bottles/containers. This shows that plastics are noncorrosive in nature. 

Q11. Should the handle and bristles of a tooth brush be made of the same material? Explain your answer.

Answer:

No, the handle and bristles of a toothbrush cannot be made of the same material. This is because the handle has to be hard and strong while bristles have to be soft and flexible.

Q12. ‘Avoid plastics as far as possible’. Comment on this advice.

Answer:

Although plastics have many properties which makes it very useful in our daily lives, yet we should try to avoid them as far as possible. This is because plastics are non-biodegradable. The waste created by plastics is not environment-friendly, which on burning release poisonous gases. Plastics may take years to degrade and keep on piling up and hence are an environmental hazard for the living community

Q 14. ‘Manufacturing synthetic fibres is actually helping conservation of forests’. Comment.

Answer:

Natural fibres like cotton, wool are obtained from plants and animals. To acquire the raw materials, trees and plants have to be chopped off hence leading to deforestation. Whereas synthetic fibres like nylon, polyester are manufactured in laboratories using chemicals or petrochemicals. Hence manufacturing fibres is actually helping the conservation of forests.  

Q15. Describe an activity to show that thermoplastic is a poor conductor of electricity.

Answer:

Aim: To show thermoplastic is a poor conductor of electricity.

Materials required: A battery, conducting copper wires, an LED bulb, a small PVC (thermoplastic) rod, a metal rod.

 

Experiment: We make a circuit as shown. First, we connect the two ends of the copper wires with the metal rod. Next, we replace it with the PVC rod.

Observation: The LED bulb glows when the metal rod is connected but does not glow when the PVC rod is connected. 

Conclusion: Thermoplastic is a poor conductor of electricity.

NCERT solutions for class 8 science: chapter-Wise

NCERT solutions for class 8 science chapter 1 Crop Production And Management

Solutions of NCERT class 8 science chapter 2 Microorganisms: Friend And Foe

CBSE NCERT solutions for class 8 science chapter 3 Synthetic Fibres And Plastics

NCERT solutions for class 8 science chapter 4 Materials: Metals And Non-Metals

CBSE NCERT solutions for class 8 science chapter 5 Coal and Petroleum

NCERT solutions for class 8 chapter 6 Combustion and Flame

Solutions of NCERT class 8 science chapter 7 Conservation of Plants and Animals

CBSE NCERT solutions for class 8 science chapter 8 Cell Structure and Functions

NCERT solutions for class 8 science chapter 9 Reproduction in Animals

Solutions of NCERT class 8 science chapter 10 Reaching the Age of Adolescence

NCERT solutions for class 8 science chapter 11 Force and Pressure

CBSE NCERT solutions for class 8 science chapter 12 Friction

Solutions of NCERT class 8 science chapter 13 Sound

NCERT solutions for class 8 science chapter 14 Chemical Effects of Electric Current

Solutions of NCERT class 8 science chapter 15 Some Natural Phenomena

CBSE NCERT solutions for class 8 science chapter 16 Light

Solutions of NCERT class 8 science chapter 17 Stars and The Solar System

NCERT solutions for class 8 science chapter 18 Pollution of Air and Water

NCERT Solutions For Class 8: Subject-Wise

                     NCERT Solutions for Class 8 Maths

                      NCERT Solutions for Class 8 Science

Benefits of NCERT Solutions for Class 8 Science Chapter 3 Synthetic Fibres and Plastics:

  • Homework is an easy task with the NCERT Solutions for Class 8 Science Chapter 3 Synthetic Fibres and Plastics in hand.
  • Similar type questions in the NCERT exercise are expected in the class exams. This is where the NCERT Solutions for Class 8 Science Chapter 3 Synthetic Fibres and Plastics is important.
  • You can score well in the exam with the help of these solutions of NCERT Class 8 Science Chapter 3 - Synthetic Fibres and Plastic
  • It will give you in-depth knowledge of your subject.

 Study Well!

 

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