NCERT Solution For Class 8 Science Chapter 3 Synthetic Fibres and Plastics

Class 8 Science Chapter 3 Synthetic Fibres and Plastics

NCERT Solution For Class 8 Science Chapter 3 Synthetic Fibres and Plastics, (Science) exam are Students are taught thru NCERT books in some of state board and CBSE Schools.  As the chapter involves an end, there is an exercise provided to assist students prepare for evaluation.  Students need to clear up those exercises very well because the questions withinside the very last asked from those. 

Sometimes, students get stuck withinside the exercises and are not able to clear up all of the questions.  To assist students solve all of the questions and maintain their studies without a doubt, we have provided step by step NCERT Solutions for the students for all classes.  These answers will similarly help students in scoring better marks with the assist of properly illustrated Solutions as a way to similarly assist the students and answering the questions right.

NCERT Solution For Class 8 Science Chapter 3 Synthetic Fibres and Plastics

Class 8 Science Chapter 3 Synthetic Fibres and Plastics

Exercise Questions

1. Explain why some fibres are called synthetic.

Solution:

Some fibres are called as synthetic fibers because these are manmade fibers prepared by using chemicals. These are made of small units that join together to form long chains. Some of the examples of synthetic fibres are nylon, rayon, acrylic, polyester etc.

2. Mark 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.

Solution:

Answer is (b) it is obtained from wood pulp.

3. 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 __________

Solution:

(a) Synthetic fibres are also called artificial or manmade fibres.

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

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

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

Solution:

Following are the examples that indicate nylon fibres are very strong

  • Parachutes and ropes of rock climbing are made of nylon
  • Nylon is used in making seat belts, fishing nets and tyre cords.
  • Nylon is used in making sports accessories like rackets.

5. Explain why plastic containers are favored for storing food.

Solution:

Because plastic is non-reactive and will not react with the ingredients of the food items.

6. Explain the difference between thermoplastic and thermosetting plastics.

Solution:

The difference between the thermosetting plastics and thermoplastics are

Thermosetting plasticThermoplastic
Cannot be bent, it will break if we attempt to bend thermo setting plasticThermoplastic can be bent easily
On heating thermosetting plastics, it cannot be softened. This is the reason it cannot be reshaped once it is molded.On heating the thermoplastics, it becomes softened and can be molded and reshaped easily.

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

(a) Saucepan handles

(b) Electric plugs/switches/plug boards

Solution:

a) Thermosetting plastics are used to make saucepan handles because they are bad conductors of heat and also on heating, these plastics do not get softened.

b) Bakelite is a kind of thermosetting plastic which is a bad conductor of heat and electricity. Because of this property it is used for making electric plugs, switches, plug boards, etc.

8. 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.

Solution:

Can be RecycledCannot be recycled
Plastic chairsCooker handles
Plastic bowlsElectrical switches
Plastic toystelephone
The plastic covering on electrical wires
Carry bags
Ballpoint pens

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

Solution:

Rana should buy a cotton shirt for the summer and not a synthetic shirt. Cotton is a good absorber of water. So it can soak the sweat coming out of the body and expose it to the environment. Thus, it helps in evaporating the sweat and helps in cooling our body.

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

Solution:

Plastics are non-corrosive in nature, they do not react even if they come in contact with strong chemicals. For example, the cleaning chemicals that we use at home are stored in plastic bottles, instead of metal containers.

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

Solution:

The handle and bristle of a toothbrush should not be made of the same material as the handle of the toothbrush should be hard and strong while the bristle should be soft and flexible.

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

Solution:

We should avoid plastics as far as possible because plastics are non-biodegradable in nature. Once introduced into the environment they cause pollution. If burnt they release poisonous gases and the the plastic bags thrown in the garbage dumb are swallowed by animals choke their respiratory system and causes fatalities in animals.

13. Match the terms of column A correctly with the phrases given in column B

AB
(i) Polyester(a) Prepared by using wood pulp
(ii) Teflon(b) Used for making parachutes and stockings
(iii) Rayon(c) Used to make non-stick cookwares
(iv) Nylon(d) Fabrics do not wrinkle easily

Solution:

AB
(i) Polyester(d) Fabrics do not wrinkle easily
(ii) Teflon(c) Used to make non-stick cookwares
(iii) Rayon(a) Prepared by using wood pulp
(iv) Nylon(b) Used for making parachutes and stockings

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

Solution:

The manufacturing of synthetic fibers is helpful in the conservation of forests because if we use natural fibers, the raw materials for them have to be derived from the plants, which require cutting off lots of trees. This proves to be helpful in the conservation of forests.

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

Solution:

In order to show that thermoplastic is a poor conductor of electricity, we will design a circuit. For that, we need a bulb, some wires, a battery, a piece of metal and a plastic pipe (as shown in the figure below). After setting the experiment switch on the current, you will observe that the bulb glows in the former case. In the latter case, the bulb does not glow. Hence a plastic pipe (which is a thermoplastic) is shown to be a poor conductor of electricity.

Benefits of NCERT Solutions for Class 8

NCERT Solutions for Class 8 contains extremely important points, and for each chapter, each concept has been simplified to make it easier to remember and increase your chances of achieving excellent exam results. Exam Preparation References Here are some tips on how these Solutions can help you prepare for the exam.

  1. This helps students solve many of the problems in each chapter and encourages them to make their concepts more meaningful.
  2. NCERT Solutions for Class 8 encourage you to update your knowledge and refine your concepts so that you can get good results in the exam.
  3. These NCERT Solutions For Class 8 are the best exam materials, allowing you to learn more about your week and your strengths. To get good results in the exam, it is important to overcome your weaknesses.
  4. Most of the questions in the exam are formulated in a similar way to NCERT textbooks. Therefore, students should review the Solutions in each chapter in order to better understand the topic.
  5. It is free of cost.

Tips & Strategies for Class 8 Exam Preparation

  1. Plan your course and syllabus and make time for revision
  2. Please refer to the NCERT Solutions available on the cbsestudyguru website to clarify your concepts every time you prepare for the exam.
  3. Use the cbsestudyguru learning app to start learning to successfully pass the exam. Provide complete teaching materials, including resolved and unresolved tasks.
  4. It is important to clear all your doubts before the exam with your teachers or Alex (an Al study Bot). 
  5. When you read or study a chapter, write down algorithm formulas, theorems, etc., and review them quickly before the exam.
  6. Practice an ample number of question papers to make your concepts stronger. 
  7. Take rest and a proper meal.  Don’t stress too much. 

Why opt for cbsestudyguru NCERT Solutions for Class 8 ? 

  • cbsestudyguru provide NCERT Solutions for all subjects at your fingertips.
  • These Solutions are designed by subject matter experts and provide Solutions to every NCERT textbook questions. 
  • cbsestudyguru especially focuses on making learning interactive, effective and for all classes.
  • We provide free NCERT Solutions for class 8 and all other classes.

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