Nylon is used for making textiles like sarees, shirts, neck-ties, tights, socks, and other garments. At the free end suspend a pan so that weight can be placed in it. It is also used to insulate the hollow walls of the refrigerator. Nylon is used in making curtains, sleeping bags and tents. 3. List two disadvantages of synthetic fibres. Rayon is used in textile industry for making clothes like sarees, blouses, dresses etc. 2) Name the man-made fibre prepared from natural materials. NCERT Exemplar for Class 8 Science Chapter 3 Synthetic Fibres and Plastics 7. Ans: Any material which can be melded into any desirable shape on heating is called plastic. Another name for this compound is artificial silk (5) Down 5. Jewelry. A plastic used for making containers and carry bags (9) 3. In thermoplastics, the long polymer chains are not cross-linked with one another. They do not get rusted when exposed to moisture and air. Ans: PET is a very popular form of polyester.  Making bandages, syringe and some another surgical dressings. Do you think rayon when burnt will stick to the body like other synthetic fibres? Why? Two example of each type of plastics are given below : 30) Why are thermoplastics not used for making frying pan handles ? Biodegradable and non-biodegradable wastes should be separated and disposed off separately. "The Material of a Thousand Uses" Bakelite's properties make it suitable for several uses including a molding compound, binding agent, varnish, and protective coating. used as a non-stick coating on pans and other cooking utensils. Synthetic Fibres and Plastics - Chapter Wise CBSE Solved Question and Answer Based On NCERT. b> synthetic fibres are made from raw materials called RAYON. Discuss the reasons for this. For example : Cotton, Jute. ... (polyvinyl chloride) is a thermoplastic and is used for making toys, chappals, etc. There more than 100 questions with answers based on Class 8 Science Chapter 3 NCERT Textbook. 2) It is harder than other plastics.Uses: It is used to make electrical goods, combs, fountain pens, buttons, plugs and switches. Bakelite: Bakelite is phenol formaldehyde resin with monomer chemical formula of (C 6-H 6-O.C-H 2-O). It is used for making gaskets, pump packings, valves, seals etc. Ans: The disposal of plastic wastes is a major problems. (b) Synthetic fibres melt on heating and sticks to the body of the person wearing it(c) It is non biodegradable and causes soil pollution. So that’s why we should not wear cloths made of synthetic fibres while working on the kitchen. It is used to make thermocol. Dr. Paustenbach used the Bakelite® simulation study as an example of how dose reconstruction could be used to cast doubt about the toxicity of an asbestos product. It is also used to make various kitchenware products like frying pans etc. Explain why the following are made of thermosetting plastics. List three steps you can take to reduce the danger that plastics pose to the environment. Melamine is used for making floor tiles, kitchenware etc. Frying pan handles are made with thermosetting plastics which are resistant to fire and can tolerate heat better than other plastics. We should not throw polythene bags,  wrappers of chips, biscuits and other eatables in water bodies, on the roads, or picnic spots. View Answer. Ans: The three R’s stand for : Reduce, Reuse, Recycle. Bakelite is a synthetic plastic resin first produced over a century ago, and used in thousands of applications. The fibres are crystalline in nature and have sharp melting points. Fishing nets are made from— nylon —. Question 1.Electrical switches are made of(a) nylon(b) bakelite(c) polythene(d) melamineAnswer:(b), Question 2.Out of the following, which is not biodegradable ? Your email address will not be published. C. SHORT-ANSWER QUESTIONS (TYPE I): Answer in a sentence or two. NCERT Exemplar Class 8 Science Chapter 3 Synthetic Fibres and Plastics. Clay is a ‘plastic’ material. Answer – Saucepan handles are made of thermosetting plastics because thermosetting plastics are poor conductor of heat. 5. Another name for this compound is artificial silk (5) Down 5. A plastic used for making containers and carry bags (9) 3. These phenolic and bakelite are of Grade A quality and come in a liquid-like appearance. It can be explained as follows : both the two plastics are made up of long chain molecules called polumers. 10. MCQ Questions for Class 8 Science with Answers were prepared based on the latest exam pattern. Uses: It is used as a non-stick coating on pans and other cooking utensils. It is used for making electric switches,plugs and sockets because Principle in the context of use of plastics ? Reference. Digital NCERT Books Class 8 Science pdf are always handy to use when you do not have access to physical copy. Thus, manufacturing of synthetic fibres is actually helping in the conservation of forests. Plastic pollution, harmful accumulation of synthetic plastic products in the environment. (a) Plastic bowls(b) PVC(c) Polystyrene(d) NylonAnswer:(b). A synthetic fibre classified as polyester (8) 7. A plastic used for making containers and carry bags (9) 3. Bakelite due to its high resistance to electricity and heat is used in automotive components and industrial applications. Which property of plastics makes them so useful but also makes them an environmental hazard? Repeat the same activity with threads of wool, polyester, silk and nylon. They are inflammable. NCERT Exemplar Class 8 Science Unit 3 Synthetic Fibres and Plastics. 3.– rubber — is used in conveyor belts. Biodegradable : Woolen clothes, paper, peels of vegetables and fruits, cotton clothes, jute bag. Ans: Two uses of Bakelite is. Plastics are persistent large-scale pollutants, and plastic debris (such as bottles, straws, containers, and plastic wrap) and particulates have been found in many environmental niches, from Mount Everest to … Synthetic fibres catch fire easily. for example : Bakellite , melanin, Formaldehyde Thermoplastic Plastic are kind of plastic which can be moulded again and again by heating and easily reused.For example :PVS, Polysterine , nylon , polythine. 2) It is harder than other plastics. Raw materials used in the preparation of bakelite are :-phenol and formaldehyde. The burning of plastic wastes gives out harmful gases which pollute the air. Packages that use Symbol.Sequence ; Package Description; org.apache.avro.io.parsing Chapter 1. Owing to its resistance to heat, electricity, and chemical action, today, Bakelite is used to make: Bases and sockets for light bulbs. 22) What is PET ? Bakelite is a phenol-formaldehyde resin. Bakelite continues to be used for wire insulation, brake pads and related automotive components, and industrial electrical-related applications. 6)Name the fibre used for making parachutes and rock climbing ropes. The name of two synthetic fibres are: Rayon, Nylon. Can you write the major difference between these two types of plastics? (d) The properties and uses of bakelite are as follows: Properties: 1) It is a good electrical insulator. Also after the chapter you can get links to Class 8 Science Notes, NCERT Solutions, Important Question, Practice Papers, etc. Bakelite has a high resistance to heat and chemicals and also has a low electrical conductivity due to which it is most commonly used for making electrical switches Bakelite is also used to make the handles of a variety of utensils. Its help you to complete your homework. Ans: Plastic do not react with air and water. List and explain four properties of plastics. Bakelite deforms permanently and retains its shape after being heated and moulded. Polyvinyl chloride – making electric wires, pipes, garden hoses etc. (d) The properties and uses of bakelite are as follows: Properties: 1) It is a good electrical insulator. Acrylic fibre is made from a chemical called ‘acrylonitrile’ by the process of polymerisation. This weight indicates the strength of the fibre. NCERT Class 8 Science Unit 3 is for Synthetic Fibres and Plastics. The articles which are made of plastics are non bio-degradable and also they don’t decompose easily. Bakelite:It is a very hard and tough plastic.It is a poor conductor of heat and electricity. On the other hand, thermosetting plastics, the long polymer chains are cross linkeds with one another . Give two examples of each. MySqlBulkLoader Constructor . Uses It is used in making bottles. Why? They melt on heating and stick to the body of the person wearing them which causes severe burn injuries. Required fields are marked *. This is why plastic bottles are commonly used to store chemicals in a chemistry laboratory. 3) Name the man-made fibre which is regarded as artificial silk ? ‘Wood pulp’ is dissolved in an alkaline solution (sodium hydroxide solution) to form a sticky liquid called ‘viscose’. Ans: Acrylic is a synthetic fibre. 3, Give the characteristic properties and important uses of the following:a. polythene b. polystyrene c. Teflon d. Bakelite. A synthetic fibre classified as polyester (8) 7. This makes the dirty drains water to flow over the streets and roads causing unhygienic conditions. Therefore, these type of clothes are not suitable in a kitchen. The process of the formation of polymers is called polymerization. Bakelite is a thermosetting plastic and is used for making electrical switches, handles of various utensils, etc. b> if the plastic bags thrown carelessly, the animals will eat up along with the left over food and vegetables and that plastic wastes choke the respiratory system   or lining in their stomach. Tabulate the data as shown in Table 3.1. Next Next Chapter 4 >> Class 8 Science Question-answers. Careless disposal of plastic bags, chokes, drains and blocks the soil. These are widely used for making clothes, nets, ropes, gauzes, etc. Although Bakelite was the trade name of the first thermosetting phenolic resin, it was not the only one. The fibres are then spun into yarns and woven into clothes. Uses: Polythene sheets are used for the packaging of liquids such as milk. Synthetic fibres are also called ……….. or ………. (c) Bakelite is used for making handles of frying pans. A. PVC. Thermoplastics : polythene and polyvinyl chloride, Thermosetting plastics : melamine and Bekalite. State the important properties of nylon. D.SHORT-ANSWER QUESTIONS (TYPE II): Answer in about 30 words. 25) Why should we not wear clothes made of synthetic fibres (like nylon or polyester) while working on the kitchen ? The molecules set the way batter sets in a … The reason is clothes made of synthetic fibres do not sufficient pores for the sweat to come out, evaporate and cool our body. Bakelite was used to make bowling balls, phonograph records, telephone housings, cookware, and billiard balls. It played a large role in bringing electronics into the automobile industry because it is heat and electricity resistant. 2) It is harder than other plastics. (a) Saucepan handles. Uses: It is used for the packaging of delicate materials like electronic items. for making a number of medical instruments. (b) The properties and uses of polystyrene are as follows:Properties: 1) It can be easily moulded.2) It has poor chemical resistance. 34) Should the bristle of a toothbrush be made of thermosetting plastics ? 1. Food can be stored in plastic containers, as they are resistant to chemicals in the food. New Learning Composite Mathematics SK Gupta Anubhuti Gangal Solution, Lakhmir Singh Manjit Kaur Class 8 Science 3rd Chapter Synthetic Fibres and Plastics, .Lakhmir Singh Manjit Kaur Science solution, Lakhmir Singh and Manjit Kaur Science Class 8 3rd Chapter Solution, Lakhmir Singh Manjit Kaur Class 8 Chemistry Solution, Lakhmir Singh Manjit Kaur Class 8 Science, Synthetic Fibres and Plastics Class 8 Solution, Synthetic Fibres and Plastics Lakhmir Singh and Manjit Kaur Class 8 solution,                      Thermoplastic,                  Thermosetting, 1> This plastic can be softened repeatedly by heating and can be moulded into different shapes. Ans: Thermosetting plastics are used for making those articles which may get too hot during use and are hard and rigid (so that they do not bend at all) so that’s why electric switches, plugs and sockets made of thermosetting plastics. —–synthetic——-fibre on burning, smells like burning paper. (d) The properties and uses of bakelite are as follows:Properties: 1) It is a good electrical insulator. Ans: (a) The properties and uses of polythene are as follows:Properties:1) It is water resistant.2) It is strong but flexible and can be rolled into sheets and moulded into different shapes. 2) It does not react chemically with other substances. Burning cotton smells like burning paper, whereas burning wool smells like burning hair. Learn more about the uses of polymers at vedantu.com. It was crafted into rotary-dial telephones, radios, electric guitars, appliance parts, door knobs, bangles, and more. Ans: If a person is wearing clothes made of synthetic fibres and his clothes catch fire accidently then the synthetic fibres of clothes melt and stick to body of that person causing severe burns. → It is widely used in various industries and for making a variety of household articles. Synthetic Fibres and Plastics. 1. 2. Even though it was technically made of Catalin, most collectors still reference it as a type of Bakelite. Prystal was a trade name used for a type of transparent Bakelite marketed by the American Catalin Corporation in a number of different colors. Why is it called artificial silk? Ans: Polyester is a type of synthetic fibre. (c) The properties and uses of Teflon are as follows: Properties:1) It is slippery and is not affected by heat. (ii) It is used … Centuries later the Iron Age introduced iron as the material of choice. It is also used to make jewelry articles and toys. ... Bakelite or melamine? 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