Q22 of 26 Page 1

Write the names and structures of the monomers of the following polymers:

(i) Terylene


(ii) Buna-S


(iii) Neoprene


(i) Terylene Monomer is a condensation polymer of Ethylene Glycol (HO – CH2 – CH2 – OH) and Terephthalic acid It is also known as Dacron. Terylene is formed when a mixture of ethylene glycol and terephthalic acid is heated at 420 to 460°K in the presence of zinc acetate-antimony trioxide catalyst.



(ii) Buna-S is a copolymer of Styrene and 1, 3-Butadiene (H2C = CH – CH = CH2) formed by addition polymerization.



(Structure of Buna-S)


(iii) Neoprene Monomer is Chloroprene. Neoprene is formed by free radical polymerization of chloroprene.




(Structure of Neoprene)


More from this chapter

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20

Predict the products of the following reactions :

(i)



(ii)



(iii)



21

(a) Account for the following :

(i) Cu+ is unstable in an aqueous solution.


(ii) Transition metals form complex compounds.


(b) Complete the following equation :



23

Seeing the growing cases of diabetes and depression among young children, Mr. Chopra, the principal of one reputed school organized a seminar in which he invited parents and principals. They all resolved this issue by strictly banning junk food in schools and introducing healthy snacks and drinks like soup, lassi, milk, etc. in school canteens. They also decided to make compulsory half an hour of daily physical activities for the students in the morning assembly. After six months, Mr. Chopra conducted the health survey in most of the schools and discovered a tremendous improvement in the health of the students.

After reading the above passage, answer the following questions:


(i) What are the values (at least two) displayed by Mr. Chopra ?


(ii) As a student, how can you spread awareness about this issue?


(iii) Why should antidepressant drugs not be taken without consulting a doctor?


(iv) Give two examples of artificial sweeteners.


24

(a) Account for the following :

(i) Acidic character increases from HF to HI.


(ii) There is a large difference between the melting and boiling points of oxygen and sulphur.


(iii) Nitrogen does not form pentahalide.


(b) Draw the structures of the following:


(i) ClF3


(ii) XeF4


OR


(i) Which allotrope of phosphorus is reactive and why ?


(ii) How are the supersonic jet aeroplanes responsible for the depletion of ozone layer ?


(iii) F2 has lower bond dissociation enthalpy than Cl2. Why ?


(iv) Which noble gas is used in filling balloons for meteorological observations ?


(v) Complete the following equation :