Bakelite is strong but brittle. Synthetic Fibres and Plastics - Chapter Wise CBSE Solved Question and Answer Based On NCERT. If you have one of these and want to bring back the shine on it, go through the Bakelite cleaning tips highlighted in this HomeQuicks article. So never put your Bakelite handled lids in the oven. (ii) Take a cotton carry-bag or a jute bag while going for shopping. Why are plastic bottles commonly used to store chemicals in a chemistry laboratory? (d) The properties and uses of bakelite are as follows: Properties: 1) It is a good electrical insulator. Hence, they are used to make things such as toys, buckets etc. Uses: It is used to make electrical goods, combs, fountain pens, buttons, plugs and switches. Acrylic fibre is made from a chemical called âacrylonitrileâ by the process of polymerisation. 3. these cross-links prevent the displacement of individual polymer chains on being heated. The name of two synthetic fibres are: Rayon, Nylon. Two example of each type of plastics are given below : 30) Why are thermoplastics not used for making frying pan handles ? It is a brownish solid substance and was also the first plastic ever made with synthetic components. This makes the dirty drains water to flow over the streets and roads causing unhygienic conditions. Ans: Â Some steps to save the environment from excessive plastic wastes are as follows: 48) How do carelessly thrown plastic bags affect: a> if the plastic bags thrown carelessly into the dirty water drains then the plastic bags clog (block them) them. Another name for this compound is artificial silk (5) Down 5. Plastic containers do not react with items stored in it. As ways were found to manufacture Bakelite in bright colors, it began to be used for all sorts of decorative objects, especially jewelry. Bakelite is still manufactured, however, and is used for pot handles and jewelry. The introduction of Bakelitethe worlds first synthetic plasticin 1907 marked the introduction of the Polymer Age. Tabulate the data as shown in Table 3.1. These properties make plastics useful but also make them as environmental hazard. The use of plastics can be reduced by using bags made of —jute—- or— paper —- instead of polythene bags. Substance made up of large number of smaller molecules (7) 4. Non-biodegradable : Polythene bags, Aluminium cans, Toothbrush, Electric switch, Frying pan handle. All Plastics have one common property what is it? Uses of Bakelite : (i) It is used for making electrical switches and plugs. Answer: (D) Bakelite. Download CBSE Class 8 Science Synthetic Fibres and Plastics MCQs in pdf, Science chapter wise Multiple Choice Questions free, Chapter 3Synthetic Fibres and Plastics 1 A chain of small chemical units combined to form a large single unit is called ____a) Polymerb) Polyc) Polythene Chapter 3 of Class 8 Science deals with different types of synthetic fibres with their importance in our daily life. Ans: Plastic do not react with air and water. Nylon is used for making textiles like sarees, shirts, neck-ties, tights, socks, and other garments. 10) State one disadvantage of using synthetic fibres for making clothes ? 25) Why should we not wear clothes made of synthetic fibres (like nylon or polyester) while working on the kitchen ? Ans.Â The characteristics of synthetic fibre are:- Ans: The following three steps can be taken to reduce the danger that plastics pose to the environment:(i) Do not throw plastic bags in the water bodies or on the road. 1. (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. The reasons are biodegradable products are decomposed through natural process but Non-Biodegradable products are not decomposed through natural process. (d) The properties and uses of bakelite are as follows: Properties: 1) It is a good electrical insulator. Ans:Â No, the bristle of a toothbrush can not be made of thermosetting plastics. b> synthetic fibres are made from raw materials called RAYON. In the 1930s cast Bakelite, along with many other competing phenolic resins, enjoyed a vogue in colourful costume jewelry and novelties. 1 Pick the synthetic fibre out of the following. 2) Name the man-made fibre prepared from natural materials. They do not get rusted when exposed to moisture and air. Another name for this compound is artificial silk (5) Down 5. Although Bakelite was the trade name of the first thermosetting phenolic resin, it was not the only one. For example, Bakelite is a thermosetting plastic which is a poor conductor of heat and electricity. A plastic used for making containers and carry bags (9) 3. 9. The fibres are crystalline in nature and have sharp melting points. 17) State the characteristics of synthetic fibres. ... with the invention of Bakelite by the Belgian-born American Leo Baekeland. A synthetic fibre classified as polyester (8) 7. Bakelite was used to make bowling balls, phonograph records, telephone housings, cookware, and billiard balls. ... (polyvinyl chloride) is a thermoplastic and is used for making toys, chappals, etc. Automobile distributor caps and other insulators. Our pots use genuine Bakelite handles to last the generations). Explain why the following are made of thermosetting plastics. Polythene â making polythene bags, bottles etc. 35) ExplainingÂ why plastic containers are preferred for storing food ? Polyvinyl chloride is used in furniture and clothing and has recently become famous for the construction for doors and windows. PET stands for âPoly-Ethylene Terephthalateâ. NCERT Exemplar for Class 8 Science Chapter 3 Synthetic ... Write two uses of Bakelite ? Question 21. Ans: Teflon is used for giving non-stick coating on cook wares. But we wear many dresses which are not made from silk, but they appear to resemble silk. Â Making bandages, syringe and some another surgical dressings. Believe it or not, from a chemist's perspective all these things are made of the same class of materials: Polymers. Ans: Â The various ways that we can avoid the use of plastics. MySqlBulkLoader Methods. Bakelite plastic has been used in a number of different vintage items and antique pieces such as old telephones, radios and even pieces of jewelry. Ans: Thermoplastics is a plastic which can be softened repeatedly by heating and can be moulded into different shapes thatâs why thermoplastics are not used for making frying pan handles. What is a plastic? (c) The properties and uses of Teflon are as follows: Properties:1) It is slippery and is not affected by heat. Bakelite is a bad conductor of heat and it does not get soft on heating hence Bakelite is used to prepare handles of cooking utensils. 2)It does not become soft on getting heated. 54) Thermopalstics can be softened by heat but thermosetting plastics cannot be softened by heat. Clay is a ‘plastic’ material. Bakelite Bowl with Nutcracker Promoted by Baekeland as "the material of a thousand uses", the first form was moulded, containing phenol formaldehyde, which was used for telephones, light switches, electrical insulators, car parts and many other industrial items. Melamine is used for making floor tiles, kitchenware etc. 4> they dry up quickly and are wrinkle resistant. used as a non-stick coating on pans and other cooking utensils. 3, Give the characteristic properties and important uses of the following:a. polythene b. polystyrene c. Teflon d. Bakelite. Synthetic Fibres and Plastics. Now coming to the uses of Bakelite, since this element has a low electrical conductivity and high heat resistance it can be used in manufacturing electrical switches and machine parts of electrical systems. Here we give Chapter 3 all solution of Class 8. 43)Classify the following as biodegradable and non-biodegradable materials : 44) State whether plastic is biodegradable or non-biodegradable ? Bakelite being thermosetting plastic can be used for insulating materials It is used in ceramic, wood, leather, paper, metal, and glass. (a) Saucepan handles. They melt on heating and stick to the body of the person wearing them which causes severe burn injuries. 3.– rubber — is used in conveyor belts. Owing to its resistance to heat, electricity, and chemical action, today, Bakelite is used to make: Bases and sockets for light bulbs. Repeat the same activity with threads of wool, polyester, silk and nylon. Synthetic fibres are synthesised from raw material called …………. (d) The properties and uses of bakelite are as follows:Properties: 1) It is a good electrical insulator. Required fields are marked *. Arrange the threads in order of their increasing strength. Text Book â SCIENCE. Thatâs why synthetic fibres are become so popular. Polythene pipes are used to transport liquids such as oil and water. Plastics should be recycled and reused. It played a large role in bringing electronics into the automobile industry because it is heat and electricity resistant. NCERT Class 8 Science Unit 3 is for Synthetic Fibres and Plastics. 8) Which synthetic fibre feels like wood and used as a substitute for wool ? It is one of the most important and extensively used polymers for making components and parts of various items. b> A plastic which once set, does not become soft on heating and cannot be moulded a second time, is called a thermosetting plastic. Plastic pollution, harmful accumulation of synthetic plastic products in the environment. 26) What type of shirts should we buy for summer ; cotton shirts or shirts made with synthetic materials ( like polyester) give reason for your answer ? Bakelite was first used as insulators against heat and electricity. His father strictly told him not to wear nylon clothes in the kitchen. 15)fill in the following blanks with suitable words: a> Synthetic fibres are also called MAN-MADE or ARTIFICIAL fibres. (a) Vegetable peels(b) Plastic bags(c) Cotton(d) JuteAnswer:(b), Question 3.Clothes made of which fabric are best suited for hot climate ? Packages that use Symbol.Sequence ; Package Description; org.apache.avro.io.parsing A type of fibre obtained naturally from cocoon (4) 6. These MCQ Questions on Synthetic Fibres and Plastics Class 8 with answers pave for a quick revision of the Chapter thereby helping you to enhance subject knowledge. A type of fibre obtained naturally from cocoon (4) 6. 5. Why is Bakelite used for making electrical switches? History is shaped by the materials we develop and use. 10. The use of plastics can be reduced by using bags made ofâjuteâ-orâpaperâ- instead of polythene bags. But clay is not a polymer because polymers are made up of monomer units while clay is not made up of monomer units. It is also used to make various kitchenware products like frying pans etc. Ans: The important properties of Nylon fibres are: (a) They are strong and elastic (b) They are light, wrinkle resistant and water resistance. for making a number of medical instruments. Its help you to complete your homework. Can you write the major difference between these two types of plastics? Ans: Thermosetting plastics are kind of plastic which once moulded cannot moulded again by heating. The molecules set the way batter sets in a â¦ Learn more about the uses of polymers at vedantu.com. A synthetic fibre classified as polyester (8) 7. 6)Name the fibre used for making parachutes and rock climbing ropes. Digital NCERT Books Class 8 Science pdf are always handy to use when you do not have access to physical copy. Food can be stored in plastic containers, as they are resistant to chemicals in the food. Making electric fittings such as electric switches, Making unbreakable kitchenware (cups, plates etc). MCQ Questions for Class 8 Science with Answers were prepared based on the latest exam pattern. It can be explained as follows : both the two plastics are made up of long chain molecules called polumers. This is because of the following two big disadvantages of plastics are: 47) What are the various ways to save the environment from excessive plastic wastes ? We should try to reduce the use of plastics by using other materials in their place. MySQL Connector/NET 8.0 API Reference. These are widely used for making clothes, nets, ropes, gauzes, etc. Your email address will not be published. Multiple Choice Questions Question. These characteristics make Bakelite ideal to use for components in electrical parts, such as electrical switches. All the 20 sets of online tests are free to use again and again. Nylon fibres are very strong, fairly elastic. Identify the type of plastic that can best be used to make electrical switches. ... Write two uses of Bakelite ? 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