Q4. Very short answer plzzzzzz.......
1) Give full form of PET.
2) Mention the main use of Teflon.
3) Define polymer.
4) Name the raw material from which Rayon is obtained.
5) Mention the property of Rayon that makes it more useful over silk.
6) Name different fibres and their nature present on the blended fibre Terrycot.
7) Complete: Zn + HCI →____+____
8) What is reactivity series of metals?
9) Copper doesn't give hydrogen gas with hydrochloric acid. Why?
10) Differentiate between thermoplastics and thermosets?
Answers
Answer:
1: polyethylene terephthalate (sometimes written poly(ethylene terephthalate)) 2: nonstick cooking pan and other cookware 3:a substance made of large number of similar unit bonded together 4: Rayon is obtained by wood pulp and cellulose 5: rayon is cheaper than silk.it is also more durable. Natural silk is very expensive to manufacture and even to buy. 6:Terylene and Cotton. Terrycot= Terylene + Terylene is often mixed with natural fibre like cotton to make clothes. 7:Zn+2HCl= ZnCl2+H2 8:The reactivity series is a series of metals, in order of reactivity from highest to lowest. It is used to determine the products of single displacement reactions, whereby metal A will replace another metal B in a solution if A is higher in the series 9:Copper does not react with HCl to give H2 gas. why? A . The reduction potential of copper is higher than hydrogen 10:The primary difference between the two is that Thermoset is a material that strengthens when heated, but cannot be remolded or heated after the initial forming, while thermoplastics can be reheated, remolded, and cooled as necessary without causing any chemical changes.