RBSE Class 8 Science Chapter 3: Synthetic Fibres and Plastics Solutions

Here, we are offering you the most accurate RBSE Class 8 Science Chapter 3 – Synthetic Fibres and Plastics Solutions. In addition, we are also providing you with lots of additional important questions and their answers on the same chapter. These additional questions are all based on the textbook concepts, thus would help in getting a comprehensive understanding of the topics covered in the lesson.

While preparing themselves for examinations, students need a reliable resource for the solutions to the RBSE Class 8 textbooks; we are here to give that and more! The solutions provided by us are drafted, as per the standards of the board. The solutions are elaborate and self-explanatory. You can refer them and enhance your grasp of the chapter and eventually, the complete textbook.

Rajasthan Board Class 8 Science Chapter 3: BYJU’S Important Questions & Answers

RBSE Class 8 Science Chapter 3 Objective Questions: Textbook Important Questions and Solutions

Q1. The material used for making non-stick utensils of the kitchen is

(A) PVC

(B) Polyether

(C) Teflon

(D) Rayon

Answer: (C) Teflon

Q2. Which of the following groups is of synthetic fibres?

(A) Nylon, Terylene, Rayon

(B) Compound

(C) Acrylic silk, Wool

(D) PVC, Polyether, Bakelite

Answer: (A) Nylon, Terylene, Rayon

Q3. The handles of utensils are made from

(A) Polyether

(B) Nylon

(C) PVC

(D) Bakelite

Answer: (D) Bakelite

Q4. Which is not the property of plastics?

(A) Inert

(B) Durable

(C) Lightweight

(D) Conduction of Electricity

Answer: (D) Conduction of Electricity

Q5. Thermoplastic is

(A) Bakelite

(B) Melamine

(C) Polyether

(D) None of the above

Answer: (C) Polyether

RBSE Class 8 Science Chapter 3 Fill in the blanks: Textbook Important Questions and Solutions

Q6. Synthetic fibres are also called ___________ or ___________ fibres.

Answer: artificial fibres, polymers

Q7. Rayon is also called ___________.

Answer: artificial silk

Q8. The polymerisation of acetonitryl gives ___________.

Answer: Arlon

Q9. Plastic is also a type of ___________.

Answer: synthetic polymer

RBSE Class 8 Science Chapter 3 Match the following: Textbook Important Questions and Solutions

COLUMN A COLUMN B
Q10. Rayon (a) Coating of a non-stick
Q11. Nylon (b) Artificial fibre
Q12. Thermosetting Plastic (c) Pipes
Q13 PVC (d) Clothes

Answers:

COLUMN A COLUMN B
Rayon (b) Artificial fibre
Nylon (d) Clothes
Thermosetting Plastic (a) Coating of a non-stick
PVC (c) Pipes

RBSE Class 8 Science Chapter 3 Short Answer Type Questions: Textbook Important Questions and Solutions

Q14. Why is it not advised to burn plastics and synthetic fibres?

Answer: It is not advised to burn plastics and synthetic fibres because burning these requires a lot of energy. Also, during the burning process, a lot of poisonous gases are released, which pollute the environment.

Q15. What are thermoplastics? Explain with examples.

Answer: Thermoplastics are the plastics that can be moulded easily by heating. When cooled, they become hard.

Examples of thermoplastic: PVC, polythene, polystyrene

Q16. Terecot is obtained by mixing two types of fibres. Name these fibres.

Answer: Terecot is obtained by mixing two types of fibres: Terylene and Cotton i.e. a natural fibre and a synthetic fibre.

Q17. What are non-biodegradable substances?

Answer: Those substances that cannot be degenerated or degraded by natural processes are called non-biodegradable substances.

Q18. What is polymerisation?

Answer: Polymerization is the process of creating a polymer by connecting monomers together.

RBSE Class 8 Science Chapter 3 Long Answer Type Questions: Textbook Important Questions and Solutions

Q19. Write the uses of Synthetic Fibre in our daily life.

Answer: Synthetic fibres are used in many places in our daily lives. For instance,

(i) Rayon is a synthetic fibre that is mixed with cotton to make bed sheets, curtains, carpets, etc.

(ii) Nylon, a synthetic fibre, is used for making socks, toothbrush, tent, sleeping bag, tent, curtains, etc.

(iii) Arlon is used to make reusable vacuum bags.

(iv) Dacron, which is also called Polyester, is used in making clothes, ropes, bottles, conveyor belts, etc.

Q20. Explain the statement “Do not use plastics in daily life as far as possible”.

Answer: The statement “Do not use plastics in daily life as far as possible” means that plastics should be avoided as much as possible.

Although plastics are lightweight, cheaper and resist high temperatures, they pose a great threat to the environment. Here are the reasons why plastics should not be used extensively:

(i) Plastics are non-biodegradable and can take years to degrade

(ii) They require high energy to burn and this process releases poisonous gases

(iii) When thrown into water resources, they become toxic towards aquatic life

Here is what we can do in order to reduce the use of plastic in daily life:

(i) Use jute bags instead of plastic bags.

(ii) Divide garbage into biodegradable and non-biodegradable waste and then recycle the non-biodegradable wastes.

(iii) Follow the 4R principle: reduce the use of plastic, reuse, recycle and recover the plastic.

Q21. How synthetic fibre Nylon is formed? Write its different properties.

Answer: Synthetic fibre Nylon is formed from adipic acid and hexamethylenediamine.

Properties of Nylon are as follows:

(i) Nylon is strong

(ii) It is lightweight

(iii) It is shiny and easily washable

(iv) Nylon does not wrinkle easily

(v) Clothes made from nylon soak less water and dry up quickly

(vi) Nylon clothes do not contract on washing and thus, do not require regular ironing.

RBSE Class 8 Science Chapter 3 Additional Important Questions and Solutions

Q22. What is a long chain formed by small units linked to each other called?

(A) Synthetic

(B) Polymer

(C) Single Unit

(D) Both (A) and (B)

Answer: (B) Polymer

Q23. Rayon is _________ than natural fibre and is also _________ to weave.

(A) more expensive, easy

(B) cheaper, difficult

(C) more expensive, difficult

(D) cheaper, easy

Answer: (D) cheaper, easy

Q24. Which of the following fibres is also known as polyester?

(A) Dacron

(B) Rayon

(C) Arlon

(D) Nylon

Answer: (A) Dacron

Q25. Which of these fibres looks like woollen fibre?

(A) Arlon

(B) Rayon

(C) Nylon

(D) Dacron

Answer: (A) Arlon

Q26. Curtains, sleeping bags and tents are usually made of

(A) Rayon

(B) Dacron

(C) Nylon

(D) Arlon

Answer: (C) Nylon

Q27. The synthetic fibre made by the combination of ethylene glycol and terephthalic acid is:

(A) Dacron

(B) Rayon

(C) Arlon

(D) Nylon

Answer: (A) Dacron

Q28. Clothes made from synthetic fibre ________ wrinkle on washing and thus _________ require ironing regularly.

(A) do, do

(B) do, don’t

(C) don’t, do

(D) don’t, don’t

Answer: (D) don’t, don’t

Q29. Synthetic fibres are __________ and can be used for a _________ time than natural fibres.

(A) weaker, longer

(B) stronger, longer

(C) weaker, shorter

(D) stronger, shorter

Answer: (B) stronger, longer

Q30. Synthetic fibres catch fire _________.

(A) quickly

(B) slowly

(C) weakly

(D) None of the above

Answer: (A) quickly

Q31. Synthetic fibres __________ absorb sweat as good as natural fibres do.

(A) do

(B) don’t

(C) can

(D) None of the above

Answer: (B) don’t

Q32. Once moulded into any shape, this type of plastic can not be moulded into another. What is this plastic called?

(A) Thermosetting

(B) Thermoplastic

(C) Both (A) and (B)

(D) None of the above

Answer: (A) Thermosetting

Q33. Which of these is used to make electric switches and batteries of cars, etc.?

(A) Polythene

(B) PVC

(C) Bakelite

(D) None of the above

Answer: (C) Bakelite

Q34. Which of these is used to cover the electric wires so that they become insulators?

(A) Plastic

(B) Nylon

(C) Rayon

(D) Cotton

Answer: (A) Plastic

Q35. What are the clothes of workers of fire extinguishers coated with in order to make them fire-resistant?

(A) PVC

(B) Nylon

(C) Teflon

(D) Melamine

Answer: (D) Melamine

Q36. Which of these is not a part of the 4R principle to stop pollution of the environment?

(A) Reuse

(B) Recycle

(C) Refer

(D) Recover

Answer: (C) Refer

Q37. What are natural fibres?

Answer: Fibres that are obtained from nature are called natural fibres.

Q38. What are synthetic fibres?

Answer: Fibres that are man-made through various chemical reactions are called synthetic fibres.

Q39. Give three examples of man-made fibres.

Answer: Nylon, Rayon and Polyester are three examples of man-made fibres.

Q40. What are the two elements that are mixed together to form Nylon?

Answer: Nylon is created from adipic acid and hexamethylenediamine.

Q41. What are the properties of Nylon?

Answer: Here are the properties of Nylon:

(i) strong (ii) wrinkleless (iii) light-weighted (iv) shiny lustre (v) easy to clean

Q42. Why is there a need to produce fibres synthetically?

Answer: Due to the increasing demand for fibres which can not be fulfilled by natural fibres alone, synthetic fibres came into existence. These synthetic fibres also have some special properties which make them popular.

Q43. Mention three advantages of synthetic fibres.

Answer: Here are three advantages of synthetic fibres:

(i) They are stronger than natural fibres.

(ii) They absorb less water and dry faster.

(iii) They don’t get easily damaged by bugs.

Q44. Mention two disadvantages of synthetic fibres.

Answer: Here are two disadvantages of synthetic fibres:

(i) They catch fire very easily.

(ii) They do not absorb sweat as natural fibres do.

Q45. What are plastics?

Answer: Plastics are small carbon molecules that form higher molecular mass structures. Plastics are materials that can easily change their shapes.

Q46. Give some examples of plastics?

Answer: PVC, bakelite, Teflon, polythene are all examples of plastics.

Q47. How are plastics categorized?

Answer: On the basis of structures, plastics are categorized into two:

(i) Thermosetting

(ii) Thermoplastic

Q48. List down three properties of thermosetting plastics?

Answer: The properties of thermosetting plastics are:

(i) Insoluble due to cross bonding in their structure

(ii) Resist heat

(iii) Do not melt

Q49. What are the properties that make use of plastic in daily lives so popular?

Answer: Properties that make use of plastic in daily lives so popular are:

(i) They are insulators of heat and light.

(ii) They resist high temperatures.

(iii) They are lightweight.

(iv) They are inert.

(v) They are cheaper than metals.

Q50. Describe the 4R principle to stop pollution of the environment.

Answer: To protect the environment from pollution, plastic should be recycled. As a part of the environment, we should follow the 4R principle in order to stop environmental pollution. The 4Rs are:

(i) Reduce the use of plastic

(ii) Reuse the products

(iii) Recycle them

(iv) Recover

Above-mentioned are solutions to all the questions of the RBSE textbook for Class 8 Science Chapter 3. Once you are thorough with all these, you can take the next step and solve sample papers. This will boost your confidence in this chapter as well as the entire subject. With the aid of these solutions, students will be able to prepare themselves for their examinations. For more such awesome resources, stay tuned!

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