(1) Explain three properties of plastic that makes it very very popular.Name three products made on the basis of these properties?

(2) Explain in detail,the  preparation of rayon fiber.Give reason,why is it called artificial silk?

(3) Give a detailed account of the use of  plastic?

(4) Give in detail the six steps you should follow to prevent the pollution due to  plastic?

(5) What kind of dress material will you recommend for workers in metal and chemical industries?Give reasons for your answer.

Asked by gspublicschool | 26th May, 2019, 07:40: PM

Expert Answer:

 
Ans. 1
  • Plastics are chemically unreactive. They do not react with air and water. As a result, plastics are resistant to corrosion.
  • As they can be easily moulded, they are used to make a large variety of articles having different shapes and sizes.
  • Plastics do not conduct heat and electricity. So, they are used as electrical insulators.

Ans.2

         Rayon

  • It is a man-made fibre prepared from a natural raw material called the cellulose, by chemical treatment.
  • The cellulose required for making rayon is obtained from the wood pulp.
  • So, rayon is obtained by the chemical treatment of wood pulp.
  • Threads are prepared from it with the help of machines. These threads have shine and strength, and they are known as ‘synthetic or artificial silk’.

Ans.3

     Uses of Polythene and PVC: It is used in manufacturing toys, combs, various types of containers, etc

     Uses of Bakelite: Bakelite is a poor conductor of heat and electricity. So; it is used for making electrical switches, handles of various utensils, etc.

    Uses of melamine: Melamine is a versatile material and can resist fire and tolerate heat better than other  plastics. So, it is used for making floor tiles, kitchenware and fabrics which resist fire.

 Ans. 4

  • Avoid the use of plastics as far as possible and make use of bags made of cotton or jute.
  • The biodegradable and non-biodegradable wastes should be collected and disposed separately.
  • Most of the thermoplastic wastes can be recycled.
  • As a responsible citizen, remember the 3R principle.

 Ans. 5

Dupont is the material suitable for workers in metal and chemical industries because it protects against the fire, heat or electric arc.

 

Answered by Ramandeep | 27th May, 2019, 10:38: AM