SYNTHETIC FIBRE AND PLASTIC 8

Practice Paper

Subject Chemistry (2019)

Class VIII                   Ch- SYNTHETIC FIBRE AND PLASTIC                                   

1. What are natural fibers?  
2. What are synthetic fibres?
3. Name two natural fibres obtained from plants.
4. Name two natural fibres obtained from animals.
5. What is a polymer?
6. Name a natural polymer.
7. Name a synthetic fiber that resembles silk.
8. How is rayon prepared?
9. Name the first completely synthesized fiber.
10. Name the raw material used in the synthesis of nylon.
11. Name the repeating units of polyester.
12. Name two common forms of polyester.
13. Name the raw materials used for making synthetic fibers.
14. What are thermosetting plastics?
15. Give two examples of thermoplastics. 
16. Give two examples of thermosetting plastics.
17. Why bakelite is used in making electrical switches?
18. Name the chemicals which give fruits their characteristic smell.
19. Name the two different types of plastics.
20. Name the man-made fiber made of wood pulp.
21. Name the fabric, which resembles wool.
22. Why nylon is used for making carpets, toothbrush bristles, and tyres?
23. Handles of frying pans are made of plastic. Why?
24. Electrical wires have a covering of plastic. Why? 
25. How are clothes, fabrics, and fibers are 
26. related to each other?
27. Name the syntheic fiber which is a cheap substitute of silk.
28. Why nylon is used in making clothes?
29. Although rayon is obtained from a natural source, wood pulp, yet it is a man-made fibre. Give reasons.
30. Nylon is used in making many articles. Name four of them.
31. Why polyesters are preferred over natural fibres for making dress material?
32. What is PET? What is its uses?
33. What are acrylics? What are its uses?
34. Why one should not wear polyester clothes while working in the kitchen or laboratory?
35. Why synthetic fibers are preferred as a clothing material?
36. Why melamine is used for making kitchenware and fabrics which resist fire?
37. Why plastic containers are preferred over containers made of glass and clay for storing foodstuffs?
38. Acrylic is considered as a cheap substitute of wool. Give reasons.
39. Define (i) Fabric ( ii)Cloth
40. Write the properties and uses of rayon
41. Write three characteristics of synthetic fibers.
42. Write three properties of plastics.
43. Write three disadvantages of synthetic fibers.
44. (a) Name a fiber that can be used as a cheap substitute of silk.(b)Write four properties of nylon that makes it a popular fiber for making clothes?(c) What is terylene? 
45. (a)When we say that plastics are non- biodegradable, what does it mean?(b)Write two fibre-wise practices.
46. What are the advantages of using synthetic fiber?
47. State True or False 
    (i) Nylon is a polymer.
    (ii) All polymers are natural materials.
    (iii) Polythene is thermosetting plastic.
    (iv) Starch, cellulose, proteins, silk and rubber are natural polymers.
    (v) Polyethylene terephthalate (PET) is used in making clothes.
48. Why the government is trying to ban plastic bags and promote paper bags though they are stronger than the paper bags?